Same-Sex Sexual Behavior in invertebrates is widespread and context-dependent: insights from a Systematic Synthesis

Same-Sex Sexual Behavior in invertebrates is widespread and context-dependent: insights from a Systematic Synthesis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Same-Sex Sexual Behavior in invertebrates is widespread and context-dependent: insights from a Systematic Synthesis Valeria Palma-Onetto, Constanza Millán-Medina This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7567028/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 4 You are reading this latest preprint version Abstract Same-sex sexual behavior (SSB) in invertebrates encompasses a wide range of interactions, including courtship, mounting, copulation, and pair bonding between individuals of the same sex. Through a systematic review of 219 primary studies and 12 reviews, we found evidence of SSB in 203 species, spanning arthropods, mollusks, annelids, echinoderms, nematodes, and flatworms. Reports were heavily biased toward insects, which represented nearly 90% of the dataset, reflecting research effort rather than true prevalence. Approximately three quarters of the cases were observed in natural conditions, while the remainder derived from laboratory studies. Male–male copulation and courtship accounted for the majority of reports, but female–female interactions and reciprocal behaviors were also recorded, the last particularly in hermaphroditic taxa. The main explanatory frameworks identified were mistaken identity or indiscriminate mating, social and environmental influences, and adaptive functions. While non-adaptive mechanisms remain a plausible explanation in some contexts, adaptive roles were supported by multiple cases, including enhanced mating practice, reproductive assurance, anti-predator strategies, and stress relief. Fitness consequences were rarely measured directly, but when reported they revealed both costs, such as reduced lifespan or genital injury, and benefits, such as improved reproductive success under biased sex ratios. The synthesis of available evidence suggests that SSB is not an anomaly but a flexible component of reproductive strategies in invertebrates. Rather than being maladaptive, it emerges as context-dependent behavior influenced by ecological and social pressures, and in some cases may confer selective advantages. invertebrates behavioral ecology homosexual behavior same-sex sexual behavior Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Same-sex sexual behavior (SSB), defined as any sexual interaction between individuals of the same sex, has been documented across a broad range of animal taxa, including invertebrates (Bagemihl 1999 ; Bailey and Zuk 2009 ). These interactions may involve courtship, mounting, copulation, genital contact, or pair bonding (Bailey and Zuk 2009 ). Traditionally, sexual behavior in animals has been viewed through a binary, reproduction-focused lens, centered on male-female copulation as the primary route to fitness. This perspective has shaped classical evolutionary theory by linking reproductive success exclusively to heterosexual mating and offspring production. However, growing evidence of SSB challenges this paradigm, prompting a re-evaluation of its biological relevance and the possibility that it may serve adaptive functions (Bagemihl 1999 ; Bailey and Zuk 2009 ; Richardson et al. 2024 ). The growing interest in same-sex sexual behavior (SSB) has raised important questions about its causes, functions, and evolutionary implications. As reports of SSB in invertebrates continue to accumulate, long-standing assumptions in evolutionary biology and behavioral ecology are being challenged, especially given that invertebrates comprise majority of known animal species (Eisenhauer and Hines 2021 ). With their remarkable diversity in reproductive strategies, social systems, and sexual morphologies (Eisenhauer and Hines 2021 ), invertebrates offer a powerful framework for investigating sexual behavior beyond vertebrate-centered models. Nonetheless, despite their ecological and taxonomic richness, invertebrates remain underrepresented in research on non-reproductive sexual interactions, including those involving same-sex individuals. Historically, the classical narrative in behavioral biology held that non-reproductive sexual acts were maladaptive or pathological (Ryan and Rand 1993). Early exceptions, such as male-male copulation in acanthocephalan worms (Abele and Gilchrist 1977 ), were treated as curiosities rather than integrated into broader evolutionary frameworks. In contrast, recent decades have seen a surge in interest and data, leading to the recognition that SSB is neither rare nor necessarily maladaptive (Scharf and Martin 2013 ; Monk et al. 2019 ; Richardson et al. 2024 ). This growing attention has been fueled in part by studies using controlled laboratory conditions, such as genetic mutants of Drosophila melanogaster that exhibit robust male-male courtship (Yamamoto and Nakano, 1999 ), and detailed behavioral observations in field and semi-natural environments, such as same-sex tandem running in termites ( Reticulitermes speratus ) under predator threat (Matsuura et al. 2002 ). These studies have moved the field beyond anecdotal observations to systematic data collection and hypothesis testing. Currently, SSB has been documented in a wide range of invertebrate taxa. For example, male-male courtship and mounting behaviors have been found to be common in beetles (Stojković et al. 2010 ), crickets (Bailey et al., 2013 ; Boutin et al. 2016 ), and parasitic wasps (Benelli et al. 2013 ). Though less studied, SSB has also been reported in spiders and millipedes (Scharf and Martin 2013 ). Limpets and squids have been observed to display complex same-sex interactions, often linked to sex change or misdirected spermatophore transfer (Rivera-Ingraham et al. 2011; Hoving and Robison 2012). Flatworms, especially the genus Macrostomum , showed reciprocal copulation and hypodermic insemination between same-sex partners (Ramm et al. 2015 ; Schärer et al. 2017). Similarly, shrimps such as Lysmata wurdemanni display sex-change behaviors influenced by the social environment, including same-sex pairings (Baeza and Bauer 2004 ). The scientific literature presents three main hypotheses to explain same-sex sexual behavior (SSB) in invertebrates: (i) mistaken identity or indiscriminate mating, (ii) social and environmental influences, and (iii) adaptive functions. The first hypothesis suggests that SSB may result from an inability to accurately distinguish sexes, especially in species with weak sexual dimorphism or under time-constrained mating conditions (Sales et al. 2018 ; Monk et al. 2019 ). For example, male crickets ( Teleogryllus oceanicus ) often attempt same-sex copulation in dense environments where sex-specific cues are limited (Bailey and French 2012 ). Similarly, hermaphroditic flatworms such as Macrostomum lign a no exhibit reciprocal copulation and hypodermic insemination between same-sex partners, potentially driven by sexual conflict or strategic sperm allocation (Schärer and Ladurner 2003; Vizoso and Schärer 2007). The second hypothesis emphasizes how social structure, and environmental context can shape SSB. In species like termites and shrimps, same-sex interactions may reflect colony dynamics or responses to ecological pressures such as sex ratio imbalances, crowding, or predation (Matsuura and Nishida 2001 ; Baeza and Bauer 2004 ). Environmental disturbances, such as flooding in Calopteryx splendens , can alter mating behavior and trigger transient same-sex interactions (Gołąb and Śniegula 2012 ). Likewise, fungal infections have been linked to increased male-male mounting in Schistocerca gregaria, possibly due to changes in sensory processing or reproductive urgency before death (Clancy et al. 2017 ). The adaptive hypothesis proposes that SSB may offer direct or indirect fitness benefits (Bailey and Zuk 2009 ; Mizumoto et al. 2016 ). These may include mating practice, social dominance, stress relief, reproductive assurance in hermaphrodites, or survival advantages. For example, in the termite R. speratus , same-sex tandem running enhances group cohesion and reduces predation risk (Matsuura et al. 2002 ; Li et al. 2013 ). Such cases suggest that SSB, far from being maladaptive, can function as context-dependent and evolutionary relevant behavior. Theoretical models by Lerch and Servedio (2007) further support how indiscriminate mating can persist under high-density conditions, while Scharf and Martin ( 2013 ) emphasized the need to view SSB as part of insects’ normal behavioral spectrum. Although SSB has been documented across numerous invertebrate taxa, its occurrence is not without potential costs. Beyond the immediate consequence of reduced reproductive output, some studies have reported additional fitness-related drawbacks. For instance, SSB has been associated with decreased lifespan in seed beetles ( Acanthoscelides obtectus ) and parasitic wasps ( Psyttalia concolor ) (Stojković et al. 2010 ; Benelli et al. 2013 ), as well as with energetic expenditures, physical harm such as genital damage in acanthocephalan worms (Abele and Gilchrist 1977 ), and diminished mating success due to less time allocated to courting females (Bailey et al. 2013 ). These findings suggest that the persistence of SSB within populations likely reflects a complex balance of costs and benefits, influenced by ecological context and selective pressures. Understanding this trade-off is essential to elucidate the evolutionary dynamics underlying SSB. Understanding the ecological and evolutionary contexts of same-sex sexual behavior (SSB) in invertebrates requires attention to both proximate mechanisms and broader adaptive frameworks. A range of neurogenetic, chemical, and environmental factors appear to regulate SSB expression (Bailey et al. 2013 ; Scharf and Martin 2013 ; Hoskins et al. 2015 ; Lane et al. 2016 ; Mizumoto et al. 2023). In model organisms like Drosophila , genes such as fruitless and doublesex control sex-specific neuronal circuits, with mutations leading to male-male courtship (Yamamoto and Nakano 1999 ; Rideout et al. 2015). More recently, transcription factors like Myc have been shown to suppress such behaviors under typical conditions, revealing the behavioral plasticity that can emerge from neural perturbations (Pan et al. 2022 ). Chemical cues, especially cuticular hydrocarbons (CHCs), also play a central role in mate recognition among insects. Alterations in these signals can result in recognition errors and same-sex interactions (Benelli and Canale 2012 ; Seidelmann 2023 ). In some cases, SSB may even be reinforced by social experience: males that have been courted by others may show heightened mating competitiveness (Benelli et al. 2013 ). This raises the possibility of feedback mechanisms and social learning in sexual behavior. From an adaptive perspective, SSB has also been interpreted as a byproduct of indiscriminate mating strategies, particularly in short-lived species or high-density populations where missing a mating opportunity may be costlier than engaging in a mistaken one (Sales et al. 2018 ; Monk et al. 2019 ). Evidence from crickets ( T. oceanicus ) and flour beetles ( Tribolium castaneum ) supports this view (Bailey and French 2012 ; Martens et al. 2024 ). However, such behaviors can be condition-dependent; for instance, male crickets in poor physiological health engage less in SSB, suggesting its expression may be sensitive to individual fitness (Richardson et al. 2024 ). As Han and Brooks ( 2015 ) demonstrated, males engaging more often in SSB achieved higher initial success under male-biased ratios, and Gavrilets and Rice (2006) argued that some alleles promoting homosexuality in one sex may increase reproductive output in the opposite sex. This suggests that the benefit of attempting to mate with a conspecific, regardless of gender, can outweigh the costs of misidentification. This systematic review aims to synthesize the current empirical and theoretical evidence on same-sex sexual behavior (SSB) in invertebrates, addressing existing gaps in the literature. Based on a broad range of taxa, including insects, arachnids, mollusks, annelids, and crustaceans, the study examines the prevalence, ecological contexts, proximate mechanisms, and potential evolutionary implications of SSB. This review includes both intentional same-sex interactions and those likely resulting from mistaken identity, indiscriminate mating, or socially mediated cues. This inclusive approach enables a comprehensive assessment of whether SSB arises from non-adaptive processes or may confer fitness benefits through adaptive functions. As same-sex sexual behavior dataset represents reported cases only, not true prevalence across taxa, it makes the data a bit opportunistic, and subject to strong reporting bias. Given that, some classic meta-analyses like calculating absolute prevalence or richness per order would be misleading. Accordingly, we focused on three guiding questions: i) what is the reported prevalence of SSB across ecological, behavioral, and taxonomic contexts in invertebrates?, ii) what proximate mechanisms have been identified to explain the occurrence of SSB, and how do these vary across lineages?, iii) to what extent is SSB explained by adaptive functions versus non-adaptive hypotheses, and what are the documented fitness consequences? Methods We systematically reviewed peer-reviewed literature (1900–2025), extracting all invertebrate SSB reports. Data included taxonomic group, sexual system, ecological context, behavioral type, and whether adaptive or non-adaptive explanations were proposed. Reviews without original data were excluded unless providing mechanistic insights. SSB was defined based on behavioral phenotype, not sexual orientation or preference, which are often inappropriate or unmeasurable constructs in invertebrate species (Bailey and Zuk 2009 ; Monk et al. 2019 ). Relevant literature was identified using advanced searches in online databases including Web of Science, Scopus, ScienceDirect, SpringerLink, and PubMed, employing combinations of search terms such as “same-sex sexual behavior,” “homosexual behavior,” and “invertebrates” alongside specific taxonomic identifiers (i.e., “arthropods,” “mollusks,” “annelids,” “flatworms”). Studies were included if they documented observable SSB in invertebrates (defined as courtship, mounting, copulation, insemination, or pairing between individuals of the same sex). Excluded were studies lacking original behavioral data or those addressing only vertebrates. From each included study, we extracted taxonomic data (phylum, order, species), description of the SSB observed, ecological setting (laboratory, field, or semi-natural), and any proposed adaptive or non-adaptive explanations. Additionally, we recorded whether fitness consequences were investigated and categorized them as positive, negative, neutral, or unknown. Because our study involved analyzing data from previous articles, it was not possible to record data blind to minimize observation bias. However, we carried a thorough revision of published data to include only studies where data was sufficiently collected, to be properly assessed as evidence for any of the proposed hypotheses. SSB mechanisms To explore variation in proximate mechanisms, associations between taxonomic groups and behavioral outcome were analyzed using generalized linear models. A phylogenetic signal test (Pagel’s λ) was conducted to assess whether SSB patterns show evolutionary conservatism within lineages, using trait mapping plus a realistic phylogenetic tree topology (equal branch lengths for simplicity). About 85 orders with no described SSB were added, while 27 orders with described SSB were included in the analysis (Tab. S1 and Tab. S2). SSB prevalence To account for variation in taxonomic effort and known species richness among functional groups, reporting rates were standardized being divided by the number of documented SSB species in that group, multiplying by 1,000 to yield a relative reporting index. This allowed us to compare documentation density rather than raw report frequency and identify groups potentially underrepresented in the literature. Descriptive statistics were used to summarize overall frequencies and types of SSB, while bar plots and heatmaps were generated to visualize behavioral patterns by group and ecological context. To determine whether observed reporting rates were significantly associated with functional group, sexual system, or ecological context, chi-square tests of independence were applied; these were aimed at identifying whether reporting biases or ecological constraints were non-randomly distributed across taxa. SSB hypotheses evaluation To evaluate the extent to which ecological or biological variables predicted whether an SSB instance was interpreted as adaptive, a binomial logistic regression model using ecological context and behavioral type as predictor variables was done. This analysis addressed the question of whether adaptive interpretations were more common in certain environments or taxa. In cases where phylogenetic information was available, the presence of SSB was phylogenetically clustered using Pagel’s λ and Blomberg’s K, which helped assess whether related species were more likely to exhibit SSB due to shared ancestry. Finally, to test the robustness of observed patterns, sensitivity analyses were conducted by excluding studies with anecdotal or weakly contextualized data, allowing to verify that trends were not disproportionately shaped by a few outliers. All statistical analyses were conducted using Python (v3.10) and R (v4.3.2), and graphical visualizations were generated using the seaborn , matplotlib , and ggplot2 packages. To strengthen the methodological framework and identify hidden patterns in SSB across invertebrate species, an unsupervised machine learning approach was performed, using KMeans clustering combined with Principal Component Analysis (PCA) for dimensionality reduction. This allowed to model latent behavioral groupings based on encoded taxonomic identity, ecological context, and SSB type. Each categorical variable was numerically encoded and subjected to clustering across the multi-dimensional space. The input features included taxonomic group, ecological context (lab, field), and SSB type (copulation, mounting, spermatophore transfer). A three-cluster KMeans model (k = 3) was selected based on visual inspection of the PCA distribution and inertia minimization. Results Taxonomic Distribution and Prevalence of SSB A total of 219 unique peer-reviewed articles and 12 reviews documenting same-sex sexual behavior (SSB) in 203 invertebrate species. The data covers a wide range of taxa including arthropods (insects, arachnids, crustaceans), mollusks (cephalopods, gastropods), annelids (polychaetes only), echinoderms (sea stars, sea urchins), and other phyla like Acanthocephala (thorny-headed worms), Nematoda, and Platyhelminthes. The publications span from 1895 to 2024, reflecting over a century of academic interest in invertebrate SSB. Within the systematic review, three hypotheses emerged as the most frequently cited to explain the occurrence of same-sex sexual behavior (SSB) in invertebrates: (i) mistaken identity or indiscriminate mating, (ii) social and environmental influences, and (iii) adaptive functions. These explanatory frameworks were present across diverse taxonomic groups (Fig. 1 ). For instance, the fruit fly Drosophila melanogaster and the red flour beetle T. castaneum each appeared in multiple investigations that linked to different hypotheses to explain SSB, from mistaken identity (Sales et al. 2018 ) to social influence (Martin et al., 2015 ) or indiscriminate mating (Martens et al. 2024 ). These repeated cases were carefully treated to avoid duplication in prevalence metrics, while still considering the variation in hypotheses and results. SSB was most frequently reported in insects, which accounted for about 89% of the documented cases in the dataset (195 articles). This was followed by much lower reporting frequencies for mollusks, crustaceans, and arachnids. After normalizing by known species richness, the relative reporting index (RRI) revealed that mega-diverse orders like Hymenoptera and Coleoptera are, in fact, significantly underrepresented in literature (Fig. 2 ). Conversely, taxa such as Odonata (dragonflies), Cephalopoda (squid), and Cidaroida (pencil urchins) were highly overrepresented. While holometabolous insects had more total reports, certain hemimetabolous groups like Odonata were particularly prominent based on their high RRI. Among other groups, marine invertebrates like polychaetes and arachnids were underrepresented, while rare but notable cases were recorded in phyla such as Acanthocephala and Nematoda. A chi-square goodness-of-fit test confirmed that the documented cases were non-randomly distributed across higher taxonomic groups, revealing a highly significant deviation from an equal distribution of reports (χ² ≈ 950, p < 0.001). This result is overwhelmingly driven by the massive number of reports in insects compared to all other groups combined. A similar test showed a significant, though less pronounced, association with ecological context, with more reports from the field than from the laboratory (χ² ≈ 57.78, p < 0.001) (Fig. 3 ). Behavioral types Common SSB behaviors observed included copulatory attempts or actual genital contact, which was the most frequently documented behavior, appearing in over half the studies and spanning numerous orders including Coleoptera, Diptera, Odonata, and Hemiptera. Courtship displays were also common, particularly in laboratory studies of Diptera, Hymenoptera, and Lepidoptera. Less frequently, mounting was explicitly recorded as a distinct behavior from copulation, alongside pair-bonding or tandem behaviors, which were noted in taxa like Isoptera (termites) and Asteroidea (sea stars). Multiple behavioral types were often recorded within a single order. While complex interactions like pairing were observed in both field (i.e., Asteroidea) and laboratory settings (i.e., Isoptera), many observations of courtship and mounting came from controlled lab studies. The data indicates that cue types vary by taxa; chemical cues such as pheromones and cuticular hydrocarbons were noted as important in insects like Hemiptera and Hymenoptera, while vibrational signals were documented in Hemiptera and chemotactic attraction was noted in Nematoda. Ecological Context and Experimental Settings The ecological context in which behaviors were observed is a key factor, with the majority of reports (approx. 76%) stemming from field observations, while a significant portion (approx. 24%) came from laboratory assays, few studies explicitly combined both contexts. SSB was robustly recorded in natural habitats, while laboratory studies often provided a controlled environment to investigate behaviors with clear ecological relevance, such as the anti-predator tandem running observed in Reticulitermes termites. The vast majority of observations were in gonochoric (separate-sexed) species, where male-male interactions such as copulation, mounting, and courtship were the most frequently recorded behaviors across numerous orders. The dataset includes a few examples of hermaphroditic or sex-changing species. In these cases, observed behaviors included male-male courtship (in the shrimp L. wurdemanni ), courtship displays (in the polychaete Ophryotrocha diadema ), and hypodermic self-insemination (in the flatworm Macrostomum hystrix ). Notably, the behaviors in some of these listed hermaphroditic species were interpreted as adaptive, such as for reproductive assurance or reducing competition (Baeza and Bauer 2004 ). Where phylogenetic analyses were included, patterns varied. The wide distribution of SSB across disparate phyla and the variety of proposed hypotheses suggest that the behavior's origins are complex, likely involving both lineage-specific predispositions and convergent evolution driven by diverse ecological and social pressures. Pagel’s λ indicated strong phylogenetic signal (λ = 0.913, p < 0.001), while Blomberg’s K suggested low-to-moderate clustering (K = 0.36, p = 0.048). SSB hypotheses testing The most frequently cited non-adaptive explanation for SSB was "mistaken identity," which was suggested for numerous species across orders like Coleoptera, Diptera, Hemiptera, and Orthoptera, often attributed to a lack of clear sex-recognition cues. Its simile, “Indiscriminate mating”, was also frequently cited as explanation for SSB. Nevertheless, various adaptive functions were also proposed. These include SSB as a mechanism to reduce male-male competition (i.e., Gnatocerus cornutus ), to practice and enhance future mating success (i.e., P. concolor ), to maximize insemination opportunities in low-visibility environments (i.e., deep-sea squid), or as an anti-predator strategy (i.e., tandem running in Reticulitermes termites). Several studies indicate that high population density increases the frequency of same-sex sexual behavior (SSB). In crowded environments, recognition errors become more likely, and individuals face stronger pressure to mate quickly before losing opportunities. A chi-square test comparing sexual system and the adaptive versus non-adaptive interpretation of behaviors yielded a significant association (χ² = 4.51, p = 0.034). Logistic regression showed that behaviors in species inhabiting high-density or high-risk environments (i.e., termites under threat) were more likely to be interpreted adaptively (z = 2.21, p = 0.027). While fitness consequences were not systematically reported, specific studies indicated costs (i.e., reduced longevity in the beetle A.s obtectus ), benefits (i.e., the adaptive functions listed above), or neutral effects (i.e., in the flour beetle T. castaneum ). To identify latent patterns in the occurrence of same-sex sexual behavior (SSB) across invertebrates, we applied PCA followed by KMeans clustering (k = 3). The dataset, which encoded taxonomic affiliation, ecological context (laboratory vs. field), and SSB type (i.e., copulation, mounting, spermatophore transfer), was reduced into two principal components for visualization. The analysis revealed three distinct clusters (Fig. 4 ). Cluster 1 contained 98 cases, Cluster 2 encompassed 70 cases, and Cluster 0 grouped 52 cases. These clusters were clearly separated in the PCA space, suggesting non-random associations among taxonomy, behavioral form, and ecological setting. Visual inspection indicated that: i) one cluster was enriched in laboratory-based reports of insects, often describing mounting or courtship under artificial density conditions; ii) a second cluster contained field observations of diverse arthropod orders, with copulation being the dominant SSB type; iii) the third cluster appeared to combine more phylogenetically distant taxa (i.e., annelids, mollusks, acanthocephalans), where SSB was typically noted as rare or incidental. Meta-analysis from N = 22 studies reporting fitness data indicated no overall significant effect (Hedges' g = 0.103; 95% CI: -0.016 to 0.222), but subgroup analyses suggest context-dependent outcomes. Strong evidence for non-adaptive drivers was found in species with rapid mating dynamics, weak sexual dimorphism, and overlapping chemical profiles. However, even in these cases, behaviors sometimes provided secondary benefits (i.e., stimulation of later heterosexual success), blurring the adaptive versus non-adaptive dichotomy. Discussion Same-sex sexual behavior was found to be taxonomically widespread and contextually diverse among invertebrates, although unevenly reported. Although previously considered as anomalous or maladaptive, SSB seems to serve functional roles, from reducing predation risk and enhancing mating skills to ensuring reproductive continuity in sex-limited environments. In this sense, SSB may be a form of evolutive behavioral plasticity, responding to ecological, social, or physiological pressures. The predominance of insects and flatworms in documented cases mirrors earlier observations (Bailey and Zuk, 2009 ; Scharf and Martin, 2013 ), yet our findings reinforce this trend likely reflects research bias rather than true behavioral frequency. Insects are frequently used in behavioral and genetic experiments due to ease of laboratory rearing, while flatworms, particularly the genus Macrostomum , offer transparent bodies and observable reproductive traits that facilitate experimental observation (Schärer et al. 2017). The significant chi-square result indicating a non-random taxonomic distribution of SSB reinforces concerns raised by Rivera-Ingraham et al. (2011) and Monk et al. ( 2019 ), who highlighted the neglect of lesser-studied marine and benthic taxa. Our standardized reporting metric helps adjust for research effort but cannot fully disentangle discovery bias from true absence of behavior. Future field surveys in underrepresented clades, such as polychaetes or echinoderms, may reveal a broader spectrum of SSB than is currently acknowledged. Ecological context showed influence on the type and interpretation of SSB. Our results confirm that laboratory environments disproportionately document behaviors such as mounting and courtship, particularly in species like D. melanogaster and T. castaneum . While controlled settings allow for standardized comparisons, they may also elicit behaviors that are rare or absent under natural conditions. This artificial inflation of certain behaviors has previously been critiqued (Bailey et al. 2013 ; Clancy et al. 2017 ), and our results corroborate those concerns by highlighting a higher frequency of maladaptive interpretations in laboratory studies. Conversely, field-based reports often document SSB behaviors with presumed non-adaptive or environmentally constrained origins, such as mistaken spermatophore implantation in Octopoteuthis deletron (Hoving and Robison 2012) or tandem pairing in C. splendens following flooding events (Gołąb and Śniegula 2012 ). These behaviors may result from temporary disruptions in sensory cues, population density, or predator-induced stress, underscoring the need to account for ecological variability when interpreting SSB. Sexual systems seem to shape SSB patterns. Hermaphroditic species such as M. lignano and L. wurdemanni frequently engage in reciprocal copulation and show high rates of adaptive interpretations, supporting the idea that flexible sex allocation strategies can promote the evolution of SSB (Schärer and Ladurner 2003; Baeza and Bauer 2004 ). The chi-square results corroborate that hermaphroditism is significantly associated with adaptive framing of SSB, echoing findings from Ramm et al. ( 2015 ), who argued that reproductive assurance, sperm competition, and social learning may all shape these behaviors. In contrast, gonochoric species, particularly insects, often exhibit unilateral SSB behaviors interpreted as mistaken identity, especially in crowded conditions or in the absence of sex-specific cues (Bailey and French 2012 ; Sales et al. 2018 ). This aligns with our regression results showing that ecological complexity, more than taxonomy or sexual system alone, predicts the likelihood of an adaptive explanation. These findings provide support for the hypothesis that SSB may emerge as a context-dependent trait modulated by external pressures rather than a fixed behavioral syndrome. In fact, under environmental stress or predator pressure, organisms may reduce the time spent on sexual discrimination, favoring indiscriminate behaviors such as rapid mounting with same-sex partners. Similarly, laboratory conditions, where densities are artificially high and environmental cues are reduced, have also been reported to exacerbate the occurrence of SSB. The phylogenetic signal detected by both Pagel’s λ and Blomberg’s K suggests a strong level of evolutionary conservatism in the presence of SSB, paralleling observations in vertebrate systems (Monk et al. 2019 ). This reinforces the conclusion that the occurrence of Same-Sex Behavior (SSB) in invertebrates shows a significant phylogenetic signal, being not randomly scattered across the invertebrate tree of life; instead, clustering within related lineages. The last suggests that both shared ancestry and convergent ecological pressures contribute to the occurrence of SSB. This nuanced view challenges earlier models that treated SSB either as entirely maladaptive (Abele and Gilchrist 1977 ) or solely as a byproduct of indiscriminate mating (Han and Brooks 2015 ). Instead, our findings suggest that SSB may represent a flexible evolutionary response shaped by lineage history and immediate social or environmental conditions. However, it must be considered that this analysis is based on reported cases, therefore, the absence of SSB in the 85 control orders is, more accurately, an absence of evidence, not necessarily evidence of absence, reflecting human research effort more than the complete distribution of animal behavior. In fact, some invertebrate groups, like fruit flies, certain beetles, and commercially relevant butterflies, are studied intensively. Their behaviors, including SSB, are well-documented, while countless other orders are cryptic, difficult to culture, live in inaccessible environments or are simply not a focus of research funding. SSB could be common in these groups but entirely unobserved. Still, even with these significant data limitations, the strong phylogenetic signal is still a very meaningful result. Instead of searching randomly, researchers can now target their efforts. Future research should focus on sister groups to the major insect orders with high rates of SSB. The unsupervised machine learning analysis provides a novel contribution to the study of animal behavior. The use of KMeans clustering, supported by PCA, revealed three distinct behavioral groupings not fully predicted by taxonomy alone. These clusters reflected: i) experimentally tractable species showing copulatory behaviors under artificial conditions, ii) adaptive reciprocators such as hermaphrodites, and iii) naturally observed species with low-frequency or error-driven behaviors. This typology aligns with frameworks proposed by Scharf and Martin ( 2013 ) and Lane et al. ( 2016 ) but provides a data-driven method for classification. The integration of artificial intelligence tools into behavioral ecology is still at an early stage. However, our results show that even basic unsupervised models can uncover meaningful patterns that enhance or even challenge expert-based classifications. Future studies could employ neural networks or ensemble models incorporating ethological metadata to refine predictions of when and where SSB is likely to evolve. This approach has the potential to revolutionize comparative behavior studies by increasing objectivity and expanding analytical scalability. Although non-adaptive hypotheses such as mistaken identity or indiscriminate mating have often been invoked to explain SSB, these mechanisms may themselves represent adaptive strategies. In certain contexts, the benefit of attempting to mate with a conspecific may exceed the costs of a misidentification, as has been proposed by Han and Brook (2015) and Gavrilets and Rice (2015). This perspective helps to explain why same-sex interactions are observed across such a wide diversity of invertebrate taxa, despite the potential fitness costs associated with injuries, wasted gametes, or reduced longevity. By reducing the risk of lost reproductive chances, these behaviors may provide a selective advantage that contributes to their persistence across evolutionary lineages. This study provides a comprehensive quantitative synthesis to date of SSB in invertebrates, spanning over four decades of research and applying both classical statistics and machine learning. In doing so, it helps bridge persistent gaps in our understanding of how sexual behavior evolves outside the vertebrate-centric framework. Our results support the growing consensus that SSB is not inherently maladaptive but may arise through diverse, often context-specific mechanisms (Bailey and Zuk, 2009 ; Mizumoto et al., 2016 ). Moreover, the findings reinforce the need for more inclusive and ecologically realistic studies of animal sexual behavior. With invertebrates comprising most of the animal diversity, continued neglect of these taxa limits the scope of evolutionary theory itself. Declarations Funding declaration This study was funded by the Programa de Apoyo a la Instalación en Investigación PA_INST_2025_25 to VPO, and by the ANID Scholarship Program 2023-21230929 to CMM. Competing interests The authors have no relevant financial or non-financial interests to disclose. Significance Statement Same-sex sexual behavior (SSB) has traditionally been viewed as anomalous or maladaptive. Our systematic synthesis across more than 200 invertebrate species demonstrates that SSB is taxonomically widespread and strongly influenced by ecological and social contexts. By integrating statistical analyses, phylogenetic signal tests, and machine learning clustering, we reveal that SSB seems to not be a random occurrence but a structured and context-dependent aspect of reproductive strategies. Evidence shows both adaptive and non-adaptive components, including benefits such as reproductive assurance, predator avoidance, and enhanced mating competence, alongside potential costs like reduced longevity. These findings underscore that SSB is not merely a byproduct of recognition errors but can serve meaningful evolutionary functions. By expanding the empirical and theoretical framework to include invertebrates, this study contributes to a broader, more inclusive understanding of sexual behavior and its evolutionary significance. Data availability statement All data generated or analyzed during this study are included in this published article and in the supplementary materials. Author contributions VPO: concept and writing of the first draft, plus the main analyses. VPO and CMM: final writing. All authors reviewed and edited the manuscript and agreed on the final version. Ethics approval statement Formal ethics approval was not necessary for this study. Permission to reproduce material from other sources No permissions were required for this work. References Abele LG, Gilchrist S (1977) Homosexual rape and sexual selection in Acanthocephalan Worms. Science 197:81–83. https://doi.org/10.1126/science.867055 Aiken RB (1981) The Relationship between Body Weight and Homosexual Mounting in Palmacorixa nana Walley (Heteroptera: Corixidae). Fla Entomol 64:267. https://doi.org/10.2307/3494579 Alcock J (1996) Male mate-locating behavior in two Australian butterflies, Anaphaeis java teutonia (Fabricius) (Pieridae) and Acraea andromacha andromacha (Fabricius) (Nymphalidae). J Res Lepid 32:1–7. https://doi.org/10.5962/p.280589 Alcock J, Buchmann SL (1985) The Significance of Post–insemination Display by Male Centris pallida (Hymenoptera: Anthophoridae). Z Tierpsychol 68:231–243. https://doi.org/10.1111/j.1439-0310.1985.tb00126.x Alexander RD (1961) Aggressiveness, Territoriality, and Sexual Behavior in Field Crickets (Orthoptera: Gryllidae). Behaviour 17:130–223 Allsopp PG, Morgan TA (1991) Male-male copulation in Antitrogus consanguineus (Blackburn) (Coleoptera: Scarabaeidae). Aust J Enomol 18(4):147–148 Ambrogio OV, Pechenik JA (2008) When is a male not a male? Sex recognition and choice in two sex-changing species. Behav Ecol Sociobiol 62:1779–1786. https://doi.org/10.1007/s00265-008-0606-4 Anderson JR, Nilssen AC, Folstad I (1994) Mating behavior and thermoregulation of the reindeer warble fly, Hypoderma tarandi L. (Diptera: Oestridae). J Insect Behav 7:679–706. https://doi.org/10.1007/BF01997439 Archer CR, Hosken DJ (2024) Resolving the puzzle of same-sex sexual interactions. Nat Rev Urol 21(4):195–196 Arita LH, Kaneshiro KY (1989) Pseudomale Courtship Behavior of the Female Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann). Pac Sci 43:2 Avosani S, Sullivan TE, Ciolli M et al (2020) Can Vibrational Playbacks Disrupt Mating or Influence Other Relevant Behaviours in Bactericera cockerelli (Triozidae: Hemiptera)? Insects 11:299. https://doi.org/10.3390/insects11050299 Baeza JA, Bauer RT (2004) Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite, the marine shrimp Lysmata wurdemanni (Caridea: Hippolytidae). Behav Ecol Sociobiol 55(6):544–550. https://doi.org/10.1007/s00265-003-0744-7 Bagemihl B (1999) Biological exuberance: Animal homosexuality and natural diversity. Macmillan, St. Martin's Bailey NW, Zuk M (2009) Same-sex sexual behavior and evolution. Trends Ecol Evol 24(8):439–446. https://doi.org/10.1016/j.tree.2009.03.014 Bailey NW, French N (2012) Same-sex sexual behaviour and mistaken identity in male field crickets, Teleogryllus oceanicus . Anim Behav 84:1031–1038. https://doi.org/10.1016/j.anbehav.2012.08.001 Bailey NW, Hoskins JL, Green J, Ritchie MG (2013) Measuring same-sex sexual behaviour: the influence of the male social environment. Anim Behav 86:91–100. https://doi.org/10.1016/j.anbehav.2013.04.016 Balfour VL, Shuker DM (2020) Same-sex sexual behaviour. Curr Biol 30(22):R1345–R1346. https://doi.org/10.1016/j.cub.2020.09.005 Barrows EM, Gordh G (1978) Sexual behavior in the Japanese beetle, Popillia japonica, and comparative notes on sexual behavior of other scarabs (Coleoptera: Scarabaeidae). Behav Biol 23:341–354. https://doi.org/10.1016/S0091-6773(78)91365-2 Barth RH (1964) The Mating Behavior of Byrsotria fumigata (Guérin) (Blattidae, Blaberinae). Behaviour 23:1–30 Bauer RT, Baeza JA (2004) Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite, the marine shrimp Lysmata wurdemanni (Caridea: Hippolytidae). Behav Ecol Sociobiol 55:544–550. https://doi.org/10.1007/s00265-003-0744-7 Benelli G, Canale A (2012) Do Psyttalia concolor (Hymenoptera: Braconidae) males gain in mating competitiveness from being courted by other males while still. young? Entomol Sci 15:257–260. https://doi.org/10.1111/j.1479-8298.2011.00503.x Benelli G, Canale A (2013) Male-male sexual behavior in the parasitic wasp Psyttalia concolor . J Insect Sci 13(1):25. https://doi.org/10.1673/031.013.2501 Benelli G, Giunti G, Messing RH, Wright MG (2013a) Visual and Olfactory Female-Borne Cues Evoke Male Courtship in the Aphid Parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae). J Insect Behav 26:695–707. https://doi.org/10.1007/s10905-013-9386-4 Benelli G, Gennari G, Francini A, Canale A (2013b) Longevity costs of same-sex interactions: first evidence from a parasitic wasp. Invertebr Biol 132:156–162. https://doi.org/10.1111/ivb.12017 Benelli G, Meregalli M, Canale A (2014a) Field Observations on the Mating Behavior of Aclees sp. cf. foveatus Voss (Coleoptera: Curculionidae), an Exotic Pest Noxious to Fig Orchards. J Insect Behav 27:419–427. https://doi.org/10.1007/s10905-014-9437-5 Benelli G, Bonsignori G, Stefanini C, Raspi A (2014b) First Quantification of Courtship Behavior in a Silver Fly, Leucopis palumbii (Diptera: Chamaemyiidae): Role of Visual, Olfactory and Tactile Cues. J Insect Behav 27:462–477. https://doi.org/10.1007/s10905-014-9443-7 Benelli G, Messing RH, Wright MG et al (2014c) Cues Triggering Mating and Host-Seeking Behavior in the Aphid Parasitoid Aphidius colemani (Hymenoptera: Braconidae: Aphidiinae): Implications for Biological Control. J Econ Entomol 107:2005–2022. https://doi.org/10.1603/EC14291 Bennett G (1974) Mating behavior of the rosechafer in northern Michigan (Coleoptera: Scarabaeidae). Coleopt Bull 167–168 Benz G (1973) Role of sex pheromone, and its insignificance for heterosexual and homosexual behaviour of larch bud moth. Experientia 29(5):553–554 Berger D, You T, Minano MR et al (2016) Sexually antagonistic selection on genetic variation underlying both male and female same-sex sexual behavior. BMC Evol Biol 16:88. https://doi.org/10.1186/s12862-016-0658-4 Berlese A (1909) Gli insetti: loro organizzazione, sviluppo, abitudini e rapporti coll'uomo, vol 1. Societa Editrice Libraria Bickel DJ, Dyte CE (1989) Family Dolichopodidae. In: Evenhuis N (ed) A catalog of the Diptera of the Australasian and Oceanian region. Honolulu, Bishop Museum Press and E.J. Brill, p 1155 Bologna M, Marangoni C (1986) Sexual behaviour in some palaearctic species of Meloe (Coleoptera Meloidae). Bollettino della Società. Entomologica Italiana 118:65–82 Boutin SRT, Harrison SJ, Fitzsimmons LP et al (2016) Same-sex sexual behaviour in crickets: understanding the paradox. Anim Behav 114:101–110. https://doi.org/10.1016/j.anbehav.2016.01.022 Bristowe WS (1929) The Mating Habits of Spiders, with special reference to the Problems surrounding Sex Dimorphisn. Proc Zool Soc Lond 99(2):309–358 Brower LP (1965) Courtship behavior of the queen butterfly, Danaus gilippus berenice (Cramer). Zoologica 50:1–39 Burgevin L, Friberg U, Maklakov AA (2013) Intersexual correlation for same-sex sexual behaviour in an insect. Anim Behav 85:759–762. https://doi.org/10.1016/j.anbehav.2013.01.017 Caballero-Mendieta N, Cordero C (2012) Enigmatic Liaisons in Lepidoptera: A Review of Same-Sex Courtship and Copulation in Butterflies and Moths. J Insect Sci 12:1–11. https://doi.org/10.1673/031.012.13801 Cane JH (1994) Nesting Biology and Mating Behavior of the Southeastern Blueberry Bee, Habropoda laboriosa (Hymenoptera: Apoidea). J Kans Entomol Soc 67:236–241 Carayon J (1966) Traumatic Insemination and the Paragenital System. Monograph of Cimicidae (Hemiptera-Heteroptera). Entomological Society of America, p 81 Castro L, Toro MA, López-Fanjul C (1994) The genetic properties of homosexual copulation behaviour in Tribolium castaneum : artificial selection. Genet Sel Evol 26(4):361–367 Chaudhuri A, Sinha AK (1994) Colleterectomy and its impact on some reproductive behaviour of the tropical Tasar silk moth, Antheraea mylitta Drury (Lepidoptera: Saturniidae). IRD 26(2): 145–152 Chin DA, Taylor DP (1969) Sexual Attraction and Mating Patterns in Cylindrocorpus longistoma and C. curzii (Nematoda: Cylindrocorporidae). J Nematol 1(4):313 Clancy LM, Cooper AL, Griffith GW, Santer RD (2017) Increased Male-Male Mounting Behaviour in Desert Locusts during Infection with an Entomopathogenic Fungus. Sci Rep 7:5659. https://doi.org/10.1038/s41598-017-05800-4 Constantz GD (1974) The Mating Behavior of a Creeping Water Bug, Ambrysus occidentalis (Hemiptera: Naucoridae). Am Midl Nat 92:234. https://doi.org/10.2307/2424220 Costanzo K, Monteiro A (2007) The use of chemical and visual cues in female choice in the butterfly Bicyclus anynana . Proc R Soc B 274:845–851. https://doi.org/10.1098/rspb.2006.3729 David WAL, Gardiner BOC (1961) The mating behaviour of Pieris brassicae (L.) in a laboratory culture. Bull Entomol Res 52:263–280. https://doi.org/10.1017/S0007485300055401 Dukas R (2010) Causes and consequences of male–male courtship in fruit flies. Anim Behav 80:913–919. https://doi.org/10.1016/j.anbehav.2010.08.017 Dunkle SW (1991) Head damage from mating attempts in dragonflies (Odonata: Anisoptera). Entomol News 102(1):37–41 Eisenhauer N, Hines J (2021) Invertebrate biodiversity and conservation. Curr Biol 31(19):R1214–R1218 Elgar MA, Pierce (1988) Mating Success and Fecundity in an Ant-Tended Lycaenid Butterfly. Reproductive success: studies of selection and adaptation in contrasting breeding systems, 59–75 Engel KC, Männer L, Ayasse M, Steiger S (2015) Acceptance threshold theory can explain occurrence of homosexual behaviour. Biol Lett 11:20140603. https://doi.org/10.1098/rsbl.2014.0603 Estrada C, Yildizhan S, Schulz S, Gilbert LE (2010) Sex-specific chemical cues from immatures facilitate the evolution of mate guarding in Heliconius butterflies. Proc R Soc B 277:407–413. https://doi.org/10.1098/rspb.2009.1476 Fianco M, Prasniewski VM (2018) Ethology of the cricket Endecous ( Endecous ) chape Souza-Dias & de Mello, 2017 (Orthoptera: Grylloidea: Phalangopsidae) I: Agonistic and reproductive behavior. JOR 27(2): 193–201 Field SA, Keller MA (1993) Courtship and intersexual signaling in the parasitic wasp (Hymenoptera: Braconidae). J Insect Behav 6:737–750. https://doi.org/10.1007/BF01201673 Finley KD, Taylor BJ, Milstein M, McKeown M (1997) dissatisfaction , a gene involved in sex-specific behavior and neural development of Drosophila melanogaster . Proc Natl Acad Sci USA 94:913–918. https://doi.org/10.1073/pnas.94.3.913 Fletcher LW, O’Grady JJ, Claborn HV, Graham OH (1966) A Pheromone from Male Screw-Worm Flies. J Econ Entomol 59:142–143. https://doi.org/10.1093/jee/59.1.142 Forsyth A, Alcock J (1990) Female mimicry and resource defense polygyny by males of a tropical rove beetle, Leistotrophus versicolor (Coleoptera: Staphylinidae). Behav Ecol Sociobiol 26. https://doi.org/10.1007/BF00171097 De Gadeau H (1896) Perversion sexuelle chez des Coléoptères mâles. Bsef 1:85–87. https://doi.org/10.3406/bsef.1896.28506 Gillespie RG (1991) Homosexual mating behavior in male Doryonychus raptor (Araneae, Tetragnathidae). JoA 19(3):229–230 Giunti G, Campolo O, Laudani F, Palmeri V (2018) Male courtship behaviour and potential for female mate choice in the black soldier fly Hermetia illucens L. (Diptera: Stratiomyidae). Entomol Gen 38(1):29–46 Gołąb MJ, Śniegula S (2012) Changes in reproductive behavior in adult damselfly Calopteryx splendens (Odonata: Calopterygidae) in response to flood. Entomol Sci 15:280–287. https://doi.org/10.1111/j.1479-8298.2012.00516.x Hafernik JE (1982) Phenetics and ecology of hybridization in buckeye butterflies (Lepidoptera: Nymphalidae), vol 96. Univ of California Hall DR, Cork A, Lester R, Zagatti P (1987) Sex pheromones of rice moth, Corcyra cephalonica Stainton. J Chem Ecol 13:1561–1573. https://doi.org/10.1007/BF00980200 Han CS, Brooks RC (2015) Same-sex sexual behaviour as a by-product of reproductive strategy under male–male scramble competition. Anim Behav 108:193–197. https://doi.org/10.1016/j.anbehav.2015.07.035 Han CS, Santostefano F, Dingemanse NJ (2016) Do social partners affect same-sex sexual behaviour in male water striders? Anim Behav 116:53–59. https://doi.org/10.1016/j.anbehav.2016.03.033 Hanks LM, Millar JG, Paine TD (1996) Mating behavior of the eucalyptus longhorned borer (Coleoptera: Cerambycidae) and the adaptive significance of long horns. J Insect Behav 9:383–393. https://doi.org/10.1007/BF02214017 Harari AR, Brockmann HJ (1999) Male beetles attracted by females mounting. Nature 401:762–763. https://doi.org/10.1038/44515 Harari AR, Brockmann HJ, Landolt PJ (2000) Intrasexual mounting in the beetle Diaprepes abbreviatus (L). Proc R Soc Lond B 267:2071–2079. https://doi.org/10.1098/rspb.2000.1251 Harris VE, Todd JW (1980) Temporal and numerical patterns of reproductive behavior in the southern green stink bug, Nezara viridula (hemiptera: pentatomidae). Entomol Exp Appl 27:105–116. https://doi.org/10.1111/j.1570-7458.1980.tb02954.x Hayes WP (1927) Congeneric and intergeneric pederasty in the Scarabaeidae (Coleop). Entomol News 38:216–218 Hay-Roe MM, Lamas G, Nation JL (2007) Pre- and postzygotic isolation and Haldane rule effects in reciprocal crosses of Danaus erippus and Danaus plexippus (Lepidoptera: Danainae), supported by differentiation of cuticular hydrocarbons, establish their status as separate species: pre- and postzygotic isolation and haldane rule effects. Biol J Linn Soc 91:445–453. https://doi.org/10.1111/j.1095-8312.2007.00809.x He XZ (2008) Reproductive Behaviour of Aphidius Ervi Haliday (Hymenoptera: Aphidiidae). Dissertation, Massey University, Palmerston North, New Zealand Heatwole H, Davis DM, Wenner AM (2010) The Behaviour of Megarhyssa , a Genus of Parasitic Hymenopterans (Ichneumonidae: Ephialtinae)1. Z Tierpsychol 19:652–664. https://doi.org/10.1111/j.1439-0310.1962.tb00796.x Henry CS (1979) Acoustical Communication during Courtship and Mating in the Green Lacewing Chrysopa carnea (Neuroptera: Chrysopidae). Ann Entomol Soc Am 72:68–79. https://doi.org/10.1093/aesa/72.1.68 Hoskins JL, Ritchie MG, Bailey NW (2015) A test of genetic models for the evolutionary maintenance of same-sex sexual behaviour. Proc R Soc B 282:20150429. https://doi.org/10.1098/rspb.2015.0429 Hoving HJT, Bush SL, Robison BH (2012) A shot in the dark: same-sex sexual behaviour in a deep-sea squid. Biol Lett 8:287–290. https://doi.org/10.1098/rsbl.2011.0680 Hoving H-JT, Fernández-Álvarez FÁ, Portner EJ, Gilly WF (2019) Same-sex sexual behaviour in an oceanic ommastrephid squid, Dosidicus gigas (Humboldt squid). Mar Biol 166:33. https://doi.org/10.1007/s00227-019-3476-6 Humphries DA (1967) The mating behaviour of the hen flea Ceratophyllus gallinae (Schrank) (Siphonaptera: Insecta). Anim Behav 15:82–90. https://doi.org/10.1016/S0003-3472(67)80016-2 Isa M, Kumano N, Tatsuta H (2019) When a male perceives a female: the effect of waxy components on the body surface on decision-making in the invasive pest weevil. R Soc open sci 6:181542. https://doi.org/10.1098/rsos.181542 Iwabuchi K (1988) Mating behavior of Xylotrechus pyrrhoderus Bates (Coleoptera: Cerambycidae). VI mating system. J Ethol 6:69–76. https://doi.org/10.1007/BF02350870 Jackson RR (1982) The biology of Portia fimbriata, a web-building jumping spider (Araneae, Salticidae) from Queensland: intraspecific interactions. J Zool 196:295–305. https://doi.org/10.1111/j.1469-7998.1982.tb03505.x Jiggins FM, Hurst GDD, Majerus MEN (2000) Sex-ratio-distorting Wolbachia causes sex-role reversal in its butterfly host. Proc R Soc Lond B 267:69–73. https://doi.org/10.1098/rspb.2000.0968 Kant R, Minor MA, Trewick SA (2012) Reproductive strategies of Diaeretiella rapae (Hymenoptera: Aphidiinae) during fluctuating temperatures of spring season in New Zealand. Biocontrol Sci Technol 22:1–9. https://doi.org/10.1080/09583157.2011.635248 Kazmi QB, Tirmizi NM (1987) An unusual behaviour in box crabs (Decapoda, Brachyura, Calappidae). Crustaceana 53(3):313–314 Keesing JK, Graham F, Irvine TR, Crossing R (2011) Synchronous aggregated pseudo-copulation of the sea star Archaster angulatus Müller & Troschel, 1842 (Echinodermata: Asteroidea) and its reproductive cycle in south-western Australia. Mar Biol 158:1163–1173. https://doi.org/10.1007/s00227-011-1638-2 Kobayashi M, Furuya H, Holland PWH (1999) Dicyemids are higher animals. Nature 401:762–762. https://doi.org/10.1038/44513 Kotyk M, Varadínová Z (2017) Wing reduction influences male mating success but not female fitness in cockroaches. Sci Rep 7:2367. https://doi.org/10.1038/s41598-017-02647-7 Kuenen LPS, Baker TC (1983) A non-anemotactic mechanism used in pheromone source location by flying moths. Physiol Entomol 8(3):277–289 Kuriwada T (2017) Male–male courtship behaviour, not relatedness, affects the intensity of contest competition in the field cricket. Anim Behav 126:217–220. https://doi.org/10.1016/j.anbehav.2017.02.009 Lane SM, Haughan AE, Evans D et al (2016) Same-sex sexual behaviour as a dominance display. Anim Behav 114:113–118. https://doi.org/10.1016/j.anbehav.2016.01.005 LeCato GL, Pienkowski RL (1970) Laboratory Mating Behavior of the Alfalfa Weevil, Hypera postica . Ann Entomol Soc Am 63:1000–1007. https://doi.org/10.1093/aesa/63.4.1000 Lecomte C, Thibout E, Pierre D, Auger J (1998) Transfer, perception, and activity of male pheromone of Acrolepiopsis assectella with special reference to conspecific male sexual inhibition. J Chem Ecol 24(4):655–671. https://doi.org/10.1023/A:1022390102631 Lerch BA, Servedio MR (2021) Same-sex sexual behaviour and selection for indiscriminate mating. Nat Ecol Evol 5(1):135–141. https://doi.org/10.1038/s41559-020-01331-w Li G, Zou X, Lei C, Huang Q (2013) Antipredator Behavior Produced by Heterosexual and Homosexual Tandem Running in the Termite Reticulitermes chinensis (Isoptera: Rhinotermitidae). Sociobiology 60:198–203. https://doi.org/10.13102/sociobiology.v60i2.198-203 Loher W, Gordon HT (1968) The Maturation of Sexual Behavior in a New Strain of the Large Milkweed Bug, Oncopeltus fasciatus ;1. Ann Entomol Soc Am 61:1566–1572. https://doi.org/10.1093/aesa/61.6.1566 Lorenzi MC, Araguas A, Bocquet C et al (2019) Courtship behavior as a war of attrition in a simultaneous hermaphrodite. Anim Biol 69:47–62. https://doi.org/10.1163/15707563-00001050 Lutz RA, Voight JR (1994) Close encounter in the deep. Nature 371(6498):563–563 Macchiano A, Razik I, Sagot M (2018) Same-sex courtship behaviors in male-biased populations: evidence for the mistaken identity hypothesis. Acta Ethol 21:147–151. https://doi.org/10.1007/s10211-018-0293-8 Martens BM, Martin OY, Janicke T, Winkler L (2024) No fitness effects of same-sex copulations in male red flour beetles. Ecol Evol 14:e11027. https://doi.org/10.1002/ece3.11027 Martin CM, Kruse KC, Switzer PV (2015) Social Experience Affects Same-Sex Pairing Behavior in Male Red Flour Beetles ( Tribolium castaneum Herbst). J Insect Behav 28:268–279. https://doi.org/10.1007/s10905-015-9498-0 Mathieu JM (1969) Mating behavior of five species of lucanidae (coleoptera: insecta). Can Entomol 101:1054–1062. https://doi.org/10.4039/Ent1011054-10 Matsuura K, Kuno E, Nishida T (2002) Homosexual Tandem Running as Selfish Herd in Reticulitermes speratus : Novel Antipredatory Behavior in Termites. J Theor Biol 214:63–70. https://doi.org/10.1006/jtbi.2001.2447 Matsuura K, Nishida T (2001) Comparison of colony foundation success between sexual pairs and female asexual units in the termite Reticulitermes speratus (Isoptera: Rhinotermitidae). Popul Ecol 43:119–124. https://doi.org/10.1007/PL00012022 Matthiesen FA (1990) Sexual behaviour and other biological aspects of the wild cockroach, Petasodes dominicana Burmeister, 1839 (Dictyoptera, Blaberidae, Blaberinae). Rev Bras Entomol 34(2):261–266 McCarthy D, Young C (2002) Gametogenesis and reproductive behavior in the echinoid Lytechinus variegatus. Mar Ecol Prog Ser 233:157–168. https://doi.org/10.3354/meps233157 Mitchem LD, Debray R, Formica VA, Brodie ED (2019) Contest interactions and outcomes: relative body size and aggression independently predict contest status. Anim Behav 157:43–49. https://doi.org/10.1016/j.anbehav.2019.06.031 Mizumoto N, Lee S-B, Chouvenc T (2024) The strength of sexual signals predicts same-sex pairing in two Coptotermes termites. Behav Ecol 35:arae067. https://doi.org/10.1093/beheco/arae067 Mizumoto N, Bourguignon T, Bailey NW (2022) Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behavior. PNAS 119(46):e2212401119. https://doi.org/10.1073/pnas.2212401119 Mizumoto N, Yashiro T, Matsuura K (2016) Male same-sex pairing as an adaptive strategy for future reproduction in termites. Anim Behav 119:179–187. https://doi.org/10.1016/j.anbehav.2016.07.007 Monk JD, Giglio E, Kamath A, Lambert MR, McDonough CE (2019) An alternative hypothesis for the evolution of same-sex sexual behaviour in animals. Nat Ecol Evol 3(12):1622–1631. https://doi.org/10.1038/s41559-019-1019-7 Mustafa SG, Spooner-Hart R, Duncan M et al (2015) Age and aggregation trigger mating behaviour in the small hive beetle, Aethina tumida (Nitidulidae). Sci Nat 102:49. https://doi.org/10.1007/s00114-015-1300-9 Nakamura H (1969) Comparative studies on the mating behaviour of two species of Callosobruchus (Coleoptera: Bruchidae). Jpn J Ecol 19:20–26 Noble LM, Chang AS, McNelis D et al (2015) Natural Variation in plep-1 Causes Male-Male Copulatory Behavior in C. elegans . Curr Biol 25:2730–2737. https://doi.org/10.1016/j.cub.2015.09.019 Noel P (1895) Accouplements anormaux chez les insectes. Misc Entomol 1:114 Nóbrega RL, Maia ACD, Lima CHMD et al (2022) Behavioral traits and sexual recognition: multiple signaling in the reproductive behavior of Cyclocephala distincta (Melolonthidae, Cyclocephalini). Acad Bras Ciênc 94:e20200694. https://doi.org/10.1590/0001-3765202220200694 Obara Y, Majerus MEN (2000) Initial Mate Recognition in the British Cabbage Butterfly, Pieris rapae rapae . Zool Sci 17:725–730. https://doi.org/10.2108/zsj.17.725 Odendaal FJ, Turchin P, Stermitz FR (1989) Influence of host-plant density and male harassment on the distribution of female Euphydryas anicia (Nymphalidae). Oecologia 78:283–288. https://doi.org/10.1007/BF00377167 Olivero P, Robillard T (2017) Same-sex sexual behavior in Xenogryllus marmoratus (Haan, 1844) (Grylloidea: Gryllidae: Eneopterinae): Observation in the wild from YouTube. JOR 26:1–5. https://doi.org/10.3897/jor.26.14569 O′Neill KM (1994) The Male Mating Strategy of the Ant Formica Subpolita Mayr (Hymenoptera: Formicidae): Swarming, Mating, and Predation Risk. Psyche 101:93–108. https://doi.org/10.1155/1994/38217 Órfão I, Calvalho C, Rodrigues I, Ascensão L, Pedaccini M, Vicente L, Barbosa M, Varela SM (2023) The role of intrasexual competition on the evolution of male-male courtship display: a systematic review. PeerJ 10:e14638. https://doi.org/10.7717/peerj.14638 Palaniswamy P, Seabrook WD, Ross RJ (1979) Precopulatory Behavior of Males and Perception of a Potential Male Pheromone in Spruce Budworm, Choristoneura fiimiferana . Ann Entomol Soc Am 72(4):544–551 Pan Y, Li W, Deng Z et al (2022) Myc suppresses male–male courtship in Drosophila . EMBO J 41:e109905. https://doi.org/10.15252/embj.2021109905 Pardi L (1987) Pseudocopulation'of females of Otiorrhynchus pupillatus cyclophtalmus (Sol.)(Col. Curculion.). Bolletino dell'Istituto di Entomologia della Università. degli Studi di Bologna 41:355–363 Parker GA (1970) The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga Stercorarial (Diptera: Scatophagidae). Behaviour 37(1–2):140–168 Peschke K (1987) Cuticular hydrocarbons regulate mate recognition, male aggression, and female choice of the rove beetle. Aleochara curuda J Chem Ecol 13(10):1993–2008. 10.1007/BF01041727 Pinto JD, Selander RB (1970) The bionomics of blister beetles of the genus Meloe and a classification of the New World species. Ill Biol Monogr 42 Piper GL (1976) Bionomics of Euarestoides acutangulus (Diptera: Tephritidae)1. Ann Entomol Soc Am 69:381–386. https://doi.org/10.1093/aesa/69.2.381 Prokopy RJ, Hendrichs J (1979) Mating Behavior of Ceratitis capitata1 on a Field-Caged Host Tree. Ann Entomol Soc Am 72:642–648. https://doi.org/10.1093/aesa/72.5.642 Qvick U (1984) A case of abnormal mating behaviour of Dolichopus popularis Wied (Diptera, Dolichopodidae). Not Entomol 64(2):93 Ramm SA, Schlatter A, Poirier M, Schärer L (2015) Hypodermic self-insemination as a reproductive assurance strategy. Proc R Soc B 282:20150660. https://doi.org/10.1098/rspb.2015.0660 Richardson J, Hoversten IP, Zuk M (2024) Male crickets in poor condition engage in less same-sex sexual behavior. Proc Natl Acad Sci USA 121:e2408811121. https://doi.org/10.1073/pnas.2408811121 Richardson J, Zuk M (2023) Rethinking same-sex sexual behaviour: male field crickets have broad mating filters. Proc R Soc B 290:20230002. https://doi.org/10.1098/rspb.2023.0002 Roberts TM, Thorson RE (1977) Chemical Attraction between Adults of Nippostrongylus brasiliensis : Description of the Phenomenon and Effects of Host Immunity. J Parasitol 63:357. https://doi.org/10.2307/3280078 Rocha CFD (1991) Composição do habitat e uso do espaço por Liolaemus lutzae (Sauria:Iguanidae) em uma área de restinga. Rev Bras Biol 51(4):839–845 Roth LM (1952) The tergal gland of the male cockroach, Supella supellectilium . J Morphol 91(3):469–477 Roth LM, Willis ER (1952) A study of cockroach behavior. Am Midl Nat 47(1):66–129 Roth LM, Barth RH (1967) The Sense Organs Employed by Cockroaches in Mating Behavior. Behaviour 28:58–94 Ryne C (2009) Homosexual interactions in bed bugs: alarm pheromones as male recognition signals. Anim Behav 78:1471–1475. https://doi.org/10.1016/j.anbehav.2009.09.033 Sales K, Trent T, Gardner J et al (2018) Experimental evolution with an insect model reveals that male homosexual behaviour occurs due to inaccurate mate choice. Anim Behav 139:51–59. https://doi.org/10.1016/j.anbehav.2018.03.004 Sanders CJ (1975) Factors affecting adult emergence and mating behavior of the eastern spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae). Can Entomol 107:967–977. https://doi.org/10.4039/Ent107967-9 Scharf I, Martin OY (2013) Same-sex sexual behavior in insects and arachnids: prevalence, causes, and consequences. Behav Ecol Sociobiol 67(11):1719–1730. https://doi.org/10.1007/s00265-013-1610-x Schlein Y, Galun R, Ben-Eliahu MN (1981) Receptors of sex pheromones and abstinons in Musca domestica and Glossina morsitans . J Chem Ecol 7:291–303. https://doi.org/10.1007/BF00995752 Scholes RJ, Monteiro PMS, Sabine CL, Canadell JG (2009) Systematic long-term observations of the global carbon cycle. Trends Ecol Evol 24:427–430. https://doi.org/10.1016/j.tree.2009.03.006 Seidelmann K (2023) Age-related changes in cuticular hydrocarbon bouquet and same-sex sexual behavior of mason bee males ( Osmia cornuta and O. bicornis ). Apidologie 54:54. https://doi.org/10.1007/s13592-023-01029-5 Serrano JM, Castro L, Toro MA, L࿽pez-Fanjul C (1991) The genetic properties of homosexual copulation behavior in Tribolium castaneum : Diallel analysis. Behav Genet 21:547–558. https://doi.org/10.1007/BF01066681 Shah DM, Horsch RB, Klee HJ et al (1986) Engineering herbicide tolerance in transgenic plants. Science 233(4762):478–481. 10.1126/science.233.4762.478 Shapiro AM (1990) The life histories and behavior of the Patagonian-Fuegian white butterflies Hypsochila microdice and H. galactodice (Lepidoptera: Pieridae). J NY Entomol Soc 98: 461–473 Simon D, Barth RH (2010) Sexual Behavior in the Cockroach Genera Periplaneta and Blatta : II. Sex Pheromones and Behavioral Responses1. Z Tierpsychol 44:162–177. https://doi.org/10.1111/j.1439-0310.1977.tb00991.x Solensky MJ (2004) The Effect of Behavior and Ecology on Male Mating Success in Overwintering Monarch Butterflies ( Danaus plexippus ). J Insect Behav 17:723–743. https://doi.org/10.1023/B:JOIR.0000048985.58159.0d Songvorawit N, Butcher BA, Chaisuekul C (2019) Size Does Not Matter: Same-Sex Sexual Behavior Occurred Regardless of Mandible Size in Male Stag Beetle Aegus chelifer chelifer (Coleoptera: Lucanidae). J Insect Behav 32:282–289. https://doi.org/10.1007/s10905-019-09733-w Stojković B, Jovanović DŠ, Tucić B, Tucić N (2010) Homosexual behaviour and its longevity cost in females and males of the seed beetle Acanthoscelides obtectus . Physiol Entomol 35:308–316. https://doi.org/10.1111/j.1365-3032.2010.00742.x Spence JR, Wilcox RS (1986) The mating system of two hybridizing species of water striders (Gerridae) II. Alternative tactics of males and females. Behav Ecol Sociobiol 19(2):87–95 Sturm H (1992) Mating behaviour and sexual dimorphism in Promesomachilis hispanica Silvestri, 1923 (Machilidae, Archaeognatha, Insecta). Zoologischer Anzeiger 228(1–2):60–73 Switzer PV, Forsythe PS, Kruse KC (2014) Male-male mounting and the unreliability of body size as a character for mate choice in male Japanese beetles ( Popillia japonica Newman). Zool Stud 53:53. https://doi.org/10.1186/s40555-014-0053-z Syrjämäki J (1964) Swarming and mating behaviour of Allochironomus crassiforceps Kieff.(Dipt., Chironomidae). In Annales Zoologici Fennici. Finnish Zoological Bot Publishing Board 1(2):125–145 Takeda K, Furuta T, Hamada M et al (2020) Handicap theory is applied to females but not males in relation to mate choice in the stalk-eyed fly Sphyracephala detrahens . Sci Rep 10:19684. https://doi.org/10.1038/s41598-020-76649-3 Tauber MJ (1968) Biology, behavior, and emergence rhythm of two species of Fannia (Diptera: Muscidae). Univ Calif Pubis Ent 50:3–86 Tauber MJ, Toschi CA (1965) Bionomics of Euleia fratria (loew) (diptera: tephritidae): I. Life history and mating behavior. Can J Zool 43:369–379. https://doi.org/10.1139/z65-036 Tennent WJ (1987) A note on the apparent lowering of moral standards in the Lepidoptera. Entomol Rec J Var 99:81–83 Vaias LJ, Napolitano LM, Tompkins L (1993) Identification of stimuli that mediate experience-dependent modification of homosexual courtship in Drosophila melanogaster . Behav Genet 23:91–97. https://doi.org/10.1007/BF01067558 Utzeri C, Belfiore C (1990) Tandem anomali fra Odonati. Fragm Entomol 22:271–287 Vaias LJ, Napolitano LM, Tompkins L (1993) Identification of stimuli that mediate experience-dependent modification of homosexual courtship in Drosophila melanogaster . Behav Gen 23(1):91–97. 10.1007/BF01067558 Van Gossum H, De Bruyn L, Stoks R (2005) Reversible switches between male–male and male–female mating behaviour by male damselflies. Biol Lett 1:268–270. https://doi.org/10.1098/rsbl.2005.0315 Wendelken P, Barth RH (1971) The mating behavior of Parcoblatta fulvescens (Saussure and Zehntner) (Blattaria, Blattellidae). Psyche 78(4):319–329. https://doi.org/10.1155/1971/41948 Wendelken PW, Barth RH (1985) On the significance of pseudofemale behavior in neotropical cockroaches. Psyche 92(4):493–503. 10.1155/1985/97012 Willis ER (1970) Mating Behavior of Three Cockroaches ( Latiblattella ) from Honduras. Biotropica 2:120. https://doi.org/10.2307/2989769 Wu J, Wang J, Wang Y, Hassan A (2023) Same-sex Pairs Retain Their Reproductive Capacity as a Potential Opportunity for Individual Reproductive Success in Termites. J Insect Sci 23:9. https://doi.org/10.1093/jisesa/ieac073 Yamamoto D, Nakano Y (1999) Sexual behavior mutants revisited: molecular and cellular basis of Drosophila mating. CMLS 56:634–646. https://doi.org/10.1007/s000180050458 Young CM, Tyler PA, Cameron JL, Rumrill SG (1992) Seasonal breeding aggregations in low-density populations of the bathyal echinoid Stylocidaris lineata . Mar Biol 113:603–612. https://doi.org/10.1007/BF00349704 Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 17 Sep, 2025 Editor assigned by journal 12 Sep, 2025 Submission checks completed at journal 11 Sep, 2025 First submitted to journal 08 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7567028","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":516683640,"identity":"dcfbf180-eaf4-451e-85d7-df5cd99916fb","order_by":0,"name":"Valeria Palma-Onetto","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8ElEQVRIiWNgGAWjYFAC5gYGBgMYg8EGIvgArxZGmBYQgyENIphAUAuCcZiwFoPjBxsfVxTYMZizH2zd8KPifOL8aQcYP+DVciax2fCMQTKDZU9i282eM7cTN9xOYJbAp0WyIbFNssGAmcHgQGLbDd42oBbpBDa8DpPsf9j+s8GgnsHg/MO2m3/bziXOn01AC79EYhtjg8FhBoMbiW23edsOJDbcJqjlYTPQYcd5LGc8bLstcybZeMPtxGa8fmHjTz74seFPtZw5f/Kxm28q7GTnz04++OEDHi0wwGOAYMNjigAwIKxkFIyCUTAKRioAAGXhU3DanE3TAAAAAElFTkSuQmCC","orcid":"","institution":"Federico Santa María Technical University","correspondingAuthor":true,"prefix":"","firstName":"Valeria","middleName":"","lastName":"Palma-Onetto","suffix":""},{"id":516683641,"identity":"d132bfdb-62b9-4f9c-b539-6bf49737d7fe","order_by":1,"name":"Constanza Millán-Medina","email":"","orcid":"","institution":"Universidad Católica de la Santísima Concepción","correspondingAuthor":false,"prefix":"","firstName":"Constanza","middleName":"","lastName":"Millán-Medina","suffix":""}],"badges":[],"createdAt":"2025-09-08 18:53:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7567028/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7567028/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":93336803,"identity":"f28af944-7919-4c3d-8216-1f534039560b","added_by":"auto","created_at":"2025-10-12 14:07:19","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":340898,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGraphical abstract \u003c/strong\u003eConceptual synthesis of the three main hypotheses proposed to explain same-sex sexual behavior in invertebrates: (i) Mistaken identity/indiscriminate mating, (ii) Social and environmental influences, (iii) Adaptive functions. The bottom highlights the systematic review dataset and the unsupervised clustering analysis (PCA + KMeans), which identified three major behavioral groupings: (1) laboratory insects with mounting/courtship under artificial density; (2) field-based arthropods with copulation as dominant behavior; and (3) phylogenetically distant taxa where SSB is rare or incidental. Together, these results illustrate that SSB is widespread, context-dependent, and not anomalous\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/a00a9be5e2325b1e2bc0a34f.jpg"},{"id":93338002,"identity":"e7b76de8-6995-44b6-89e0-9da95c2d6296","added_by":"auto","created_at":"2025-10-12 14:15:19","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":247401,"visible":true,"origin":"","legend":"\u003cp\u003eRelative Reporting Index (RRI × 1000) for SSB across 24 invertebrate orders. This visualization highlights both strong taxonomic biases in research effort and the uneven distribution of SSB documentation across invertebrate lineages\u003c/p\u003e","description":"","filename":"Picture2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/11b51b83fe6e8769e18922f4.jpg"},{"id":93335499,"identity":"86aa773a-c384-41a0-8350-02af10c3f166","added_by":"auto","created_at":"2025-10-12 13:59:19","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":386912,"visible":true,"origin":"","legend":"\u003cp\u003eHeatmap of reported same-sex sexual behavior (SSB) across invertebrate orders, separated by ecological context. Each cell represents the number of published reports documenting SSB in either field or laboratory conditions. Warmer colors indicate higher frequencies of reports\u003c/p\u003e","description":"","filename":"Picture3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/faef2a4a7a895f5024f02e16.jpg"},{"id":93335497,"identity":"7929b725-9e2d-44ce-b7d8-baecff6374ad","added_by":"auto","created_at":"2025-10-12 13:59:19","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":552219,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal Component Analysis biplot of invertebrate same-sex sexual behavior reports, clustered using a three-group KMeans model (\u003cem\u003ek\u003c/em\u003e= 3). Each point represents a documented case, encoded by taxonomic order, ecological context (Field or Laboratory), and SSB type (copulation, mounting, spermatophore transfer). The ellipses (semi-transparent fills with dark borders) highlight the main clusters, showing non-random associations between taxa, contexts, and behavior types. Three distinct behavioral groupings were revealed: (i) laboratory-based insect reports dominated by mounting and courtship (blue); (ii) field-based arthropod observations dominated by copulation (green); and (iii) phylogenetically distant taxa (i.e., mollusks, flatworms, annelids) where SSB appears rarer or incidental (red)\u003c/p\u003e","description":"","filename":"Picture4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/7e1eabfcff1b3bc78bf896ec.jpg"},{"id":93338840,"identity":"09948217-2d27-4ee3-a8ba-bdc78ef85718","added_by":"auto","created_at":"2025-10-12 14:23:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2190694,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/0d2efc77-8033-45e8-aa0a-02bc3e50410d.pdf"},{"id":93336801,"identity":"0dcb7a0b-3c9e-4015-b324-fa6c54fb77bb","added_by":"auto","created_at":"2025-10-12 14:07:19","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":58558,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-7567028/v1/5c37067e63b8c8b9d0014cd0.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Same-Sex Sexual Behavior in invertebrates is widespread and context-dependent: insights from a Systematic Synthesis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSame-sex sexual behavior (SSB), defined as any sexual interaction between individuals of the same sex, has been documented across a broad range of animal taxa, including invertebrates (Bagemihl \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Bailey and Zuk \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). These interactions may involve courtship, mounting, copulation, genital contact, or pair bonding (Bailey and Zuk \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Traditionally, sexual behavior in animals has been viewed through a binary, reproduction-focused lens, centered on male-female copulation as the primary route to fitness. This perspective has shaped classical evolutionary theory by linking reproductive success exclusively to heterosexual mating and offspring production. However, growing evidence of SSB challenges this paradigm, prompting a re-evaluation of its biological relevance and the possibility that it may serve adaptive functions (Bagemihl \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Bailey and Zuk \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Richardson et al. \u003cspan citationid=\"CR132\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe growing interest in same-sex sexual behavior (SSB) has raised important questions about its causes, functions, and evolutionary implications. As reports of SSB in invertebrates continue to accumulate, long-standing assumptions in evolutionary biology and behavioral ecology are being challenged, especially given that invertebrates comprise majority of known animal species (Eisenhauer and Hines \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). With their remarkable diversity in reproductive strategies, social systems, and sexual morphologies (Eisenhauer and Hines \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), invertebrates offer a powerful framework for investigating sexual behavior beyond vertebrate-centered models. Nonetheless, despite their ecological and taxonomic richness, invertebrates remain underrepresented in research on non-reproductive sexual interactions, including those involving same-sex individuals.\u003c/p\u003e\u003cp\u003eHistorically, the classical narrative in behavioral biology held that non-reproductive sexual acts were maladaptive or pathological (Ryan and Rand 1993). Early exceptions, such as male-male copulation in acanthocephalan worms (Abele and Gilchrist \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1977\u003c/span\u003e), were treated as curiosities rather than integrated into broader evolutionary frameworks. In contrast, recent decades have seen a surge in interest and data, leading to the recognition that SSB is neither rare nor necessarily maladaptive (Scharf and Martin \u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Monk et al. \u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Richardson et al. \u003cspan citationid=\"CR132\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). This growing attention has been fueled in part by studies using controlled laboratory conditions, such as genetic mutants of \u003cem\u003eDrosophila melanogaster\u003c/em\u003e that exhibit robust male-male courtship (Yamamoto and Nakano, \u003cspan citationid=\"CR169\" class=\"CitationRef\"\u003e1999\u003c/span\u003e), and detailed behavioral observations in field and semi-natural environments, such as same-sex tandem running in termites (\u003cem\u003eReticulitermes speratus\u003c/em\u003e) under predator threat (Matsuura et al. \u003cspan citationid=\"CR103\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). These studies have moved the field beyond anecdotal observations to systematic data collection and hypothesis testing.\u003c/p\u003e\u003cp\u003eCurrently, SSB has been documented in a wide range of invertebrate taxa. For example, male-male courtship and mounting behaviors have been found to be common in beetles (Stojković et al. \u003cspan citationid=\"CR152\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), crickets (Bailey et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Boutin et al. \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), and parasitic wasps (Benelli et al. \u003cspan citationid=\"CR95\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Though less studied, SSB has also been reported in spiders and millipedes (Scharf and Martin \u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Limpets and squids have been observed to display complex same-sex interactions, often linked to sex change or misdirected spermatophore transfer (Rivera-Ingraham et al. 2011; Hoving and Robison 2012). Flatworms, especially the genus \u003cem\u003eMacrostomum\u003c/em\u003e, showed reciprocal copulation and hypodermic insemination between same-sex partners (Ramm et al. \u003cspan citationid=\"CR131\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Sch\u0026auml;rer et al. 2017). Similarly, shrimps such as \u003cem\u003eLysmata wurdemanni\u003c/em\u003e display sex-change behaviors influenced by the social environment, including same-sex pairings (Baeza and Bauer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe scientific literature presents three main hypotheses to explain same-sex sexual behavior (SSB) in invertebrates: (i) mistaken identity or indiscriminate mating, (ii) social and environmental influences, and (iii) adaptive functions. The first hypothesis suggests that SSB may result from an inability to accurately distinguish sexes, especially in species with weak sexual dimorphism or under time-constrained mating conditions (Sales et al. \u003cspan citationid=\"CR140\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Monk et al. \u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). For example, male crickets (\u003cem\u003eTeleogryllus oceanicus\u003c/em\u003e) often attempt same-sex copulation in dense environments where sex-specific cues are limited (Bailey and French \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Similarly, hermaphroditic flatworms such as \u003cem\u003eMacrostomum lign\u003c/em\u003ea\u003cem\u003eno\u003c/em\u003e exhibit reciprocal copulation and hypodermic insemination between same-sex partners, potentially driven by sexual conflict or strategic sperm allocation (Sch\u0026auml;rer and Ladurner 2003; Vizoso and Sch\u0026auml;rer 2007). The second hypothesis emphasizes how social structure, and environmental context can shape SSB. In species like termites and shrimps, same-sex interactions may reflect colony dynamics or responses to ecological pressures such as sex ratio imbalances, crowding, or predation (Matsuura and Nishida \u003cspan citationid=\"CR104\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Baeza and Bauer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Environmental disturbances, such as flooding in \u003cem\u003eCalopteryx splendens\u003c/em\u003e, can alter mating behavior and trigger transient same-sex interactions (Gołąb and Śniegula \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Likewise, fungal infections have been linked to increased male-male mounting in Schistocerca gregaria, possibly due to changes in sensory processing or reproductive urgency before death (Clancy et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The adaptive hypothesis proposes that SSB may offer direct or indirect fitness benefits (Bailey and Zuk \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Mizumoto et al. \u003cspan citationid=\"CR110\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). These may include mating practice, social dominance, stress relief, reproductive assurance in hermaphrodites, or survival advantages. For example, in the termite \u003cem\u003eR. speratus\u003c/em\u003e, same-sex tandem running enhances group cohesion and reduces predation risk (Matsuura et al. \u003cspan citationid=\"CR103\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Li et al. \u003cspan citationid=\"CR95\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Such cases suggest that SSB, far from being maladaptive, can function as context-dependent and evolutionary relevant behavior. Theoretical models by Lerch and Servedio (2007) further support how indiscriminate mating can persist under high-density conditions, while Scharf and Martin (\u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) emphasized the need to view SSB as part of insects\u0026rsquo; normal behavioral spectrum.\u003c/p\u003e\u003cp\u003eAlthough SSB has been documented across numerous invertebrate taxa, its occurrence is not without potential costs. Beyond the immediate consequence of reduced reproductive output, some studies have reported additional fitness-related drawbacks. For instance, SSB has been associated with decreased lifespan in seed beetles (\u003cem\u003eAcanthoscelides obtectus\u003c/em\u003e) and parasitic wasps (\u003cem\u003ePsyttalia concolor\u003c/em\u003e) (Stojković et al. \u003cspan citationid=\"CR152\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Benelli et al. \u003cspan citationid=\"CR95\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), as well as with energetic expenditures, physical harm such as genital damage in acanthocephalan worms (Abele and Gilchrist \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1977\u003c/span\u003e), and diminished mating success due to less time allocated to courting females (Bailey et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). These findings suggest that the persistence of SSB within populations likely reflects a complex balance of costs and benefits, influenced by ecological context and selective pressures. Understanding this trade-off is essential to elucidate the evolutionary dynamics underlying SSB.\u003c/p\u003e\u003cp\u003eUnderstanding the ecological and evolutionary contexts of same-sex sexual behavior (SSB) in invertebrates requires attention to both proximate mechanisms and broader adaptive frameworks. A range of neurogenetic, chemical, and environmental factors appear to regulate SSB expression (Bailey et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Scharf and Martin \u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Hoskins et al. \u003cspan citationid=\"CR76\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Lane et al. \u003cspan citationid=\"CR91\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Mizumoto et al. 2023). In model organisms like \u003cem\u003eDrosophila\u003c/em\u003e, genes such as \u003cem\u003efruitless\u003c/em\u003e and \u003cem\u003edoublesex\u003c/em\u003e control sex-specific neuronal circuits, with mutations leading to male-male courtship (Yamamoto and Nakano \u003cspan citationid=\"CR169\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Rideout et al. 2015). More recently, transcription factors like \u003cem\u003eMyc\u003c/em\u003e have been shown to suppress such behaviors under typical conditions, revealing the behavioral plasticity that can emerge from neural perturbations (Pan et al. \u003cspan citationid=\"CR123\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Chemical cues, especially cuticular hydrocarbons (CHCs), also play a central role in mate recognition among insects. Alterations in these signals can result in recognition errors and same-sex interactions (Benelli and Canale \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Seidelmann \u003cspan citationid=\"CR145\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In some cases, SSB may even be reinforced by social experience: males that have been courted by others may show heightened mating competitiveness (Benelli et al. \u003cspan citationid=\"CR95\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). This raises the possibility of feedback mechanisms and social learning in sexual behavior. From an adaptive perspective, SSB has also been interpreted as a byproduct of indiscriminate mating strategies, particularly in short-lived species or high-density populations where missing a mating opportunity may be costlier than engaging in a mistaken one (Sales et al. \u003cspan citationid=\"CR140\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Monk et al. \u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Evidence from crickets (\u003cem\u003eT. oceanicus\u003c/em\u003e) and flour beetles (\u003cem\u003eTribolium castaneum\u003c/em\u003e) supports this view (Bailey and French \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Martens et al. \u003cspan citationid=\"CR100\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). However, such behaviors can be condition-dependent; for instance, male crickets in poor physiological health engage less in SSB, suggesting its expression may be sensitive to individual fitness (Richardson et al. \u003cspan citationid=\"CR132\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). As Han and Brooks (\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) demonstrated, males engaging more often in SSB achieved higher initial success under male-biased ratios, and Gavrilets and Rice (2006) argued that some alleles promoting homosexuality in one sex may increase reproductive output in the opposite sex. This suggests that the benefit of attempting to mate with a conspecific, regardless of gender, can outweigh the costs of misidentification.\u003c/p\u003e\u003cp\u003eThis systematic review aims to synthesize the current empirical and theoretical evidence on same-sex sexual behavior (SSB) in invertebrates, addressing existing gaps in the literature. Based on a broad range of taxa, including insects, arachnids, mollusks, annelids, and crustaceans, the study examines the prevalence, ecological contexts, proximate mechanisms, and potential evolutionary implications of SSB. This review includes both intentional same-sex interactions and those likely resulting from mistaken identity, indiscriminate mating, or socially mediated cues. This inclusive approach enables a comprehensive assessment of whether SSB arises from non-adaptive processes or may confer fitness benefits through adaptive functions. As same-sex sexual behavior dataset represents reported cases only, not true prevalence across taxa, it makes the data a bit opportunistic, and subject to strong reporting bias. Given that, some classic meta-analyses like calculating absolute prevalence or richness per order would be misleading. Accordingly, we focused on three guiding questions: i) what is the reported prevalence of SSB across ecological, behavioral, and taxonomic contexts in invertebrates?, ii) what proximate mechanisms have been identified to explain the occurrence of SSB, and how do these vary across lineages?, iii) to what extent is SSB explained by adaptive functions versus non-adaptive hypotheses, and what are the documented fitness consequences?\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe systematically reviewed peer-reviewed literature (1900\u0026ndash;2025), extracting all invertebrate SSB reports. Data included taxonomic group, sexual system, ecological context, behavioral type, and whether adaptive or non-adaptive explanations were proposed. Reviews without original data were excluded unless providing mechanistic insights.\u003c/p\u003e\u003cp\u003eSSB was defined based on behavioral phenotype, not sexual orientation or preference, which are often inappropriate or unmeasurable constructs in invertebrate species (Bailey and Zuk \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Monk et al. \u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Relevant literature was identified using advanced searches in online databases including Web of Science, Scopus, ScienceDirect, SpringerLink, and PubMed, employing combinations of search terms such as \u0026ldquo;same-sex sexual behavior,\u0026rdquo; \u0026ldquo;homosexual behavior,\u0026rdquo; and \u0026ldquo;invertebrates\u0026rdquo; alongside specific taxonomic identifiers (i.e., \u0026ldquo;arthropods,\u0026rdquo; \u0026ldquo;mollusks,\u0026rdquo; \u0026ldquo;annelids,\u0026rdquo; \u0026ldquo;flatworms\u0026rdquo;). Studies were included if they documented observable SSB in invertebrates (defined as courtship, mounting, copulation, insemination, or pairing between individuals of the same sex). Excluded were studies lacking original behavioral data or those addressing only vertebrates. From each included study, we extracted taxonomic data (phylum, order, species), description of the SSB observed, ecological setting (laboratory, field, or semi-natural), and any proposed adaptive or non-adaptive explanations. Additionally, we recorded whether fitness consequences were investigated and categorized them as positive, negative, neutral, or unknown. Because our study involved analyzing data from previous articles, it was not possible to record data blind to minimize observation bias. However, we carried a thorough revision of published data to include only studies where data was sufficiently collected, to be properly assessed as evidence for any of the proposed hypotheses.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eSSB mechanisms\u003c/h2\u003e\u003cp\u003eTo explore variation in proximate mechanisms, associations between taxonomic groups and behavioral outcome were analyzed using generalized linear models. A phylogenetic signal test (Pagel\u0026rsquo;s λ) was conducted to assess whether SSB patterns show evolutionary conservatism within lineages, using trait mapping plus a realistic phylogenetic tree topology (equal branch lengths for simplicity). About 85 orders with no described SSB were added, while 27 orders with described SSB were included in the analysis (Tab. S1 and Tab. S2).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eSSB prevalence\u003c/h3\u003e\n\u003cp\u003eTo account for variation in taxonomic effort and known species richness among functional groups, reporting rates were standardized being divided by the number of documented SSB species in that group, multiplying by 1,000 to yield a relative reporting index. This allowed us to compare documentation density rather than raw report frequency and identify groups potentially underrepresented in the literature. Descriptive statistics were used to summarize overall frequencies and types of SSB, while bar plots and heatmaps were generated to visualize behavioral patterns by group and ecological context. To determine whether observed reporting rates were significantly associated with functional group, sexual system, or ecological context, chi-square tests of independence were applied; these were aimed at identifying whether reporting biases or ecological constraints were non-randomly distributed across taxa.\u003c/p\u003e\n\u003ch3\u003eSSB hypotheses evaluation\u003c/h3\u003e\n\u003cp\u003eTo evaluate the extent to which ecological or biological variables predicted whether an SSB instance was interpreted as adaptive, a binomial logistic regression model using ecological context and behavioral type as predictor variables was done. This analysis addressed the question of whether adaptive interpretations were more common in certain environments or taxa. In cases where phylogenetic information was available, the presence of SSB was phylogenetically clustered using Pagel\u0026rsquo;s λ and Blomberg\u0026rsquo;s K, which helped assess whether related species were more likely to exhibit SSB due to shared ancestry. Finally, to test the robustness of observed patterns, sensitivity analyses were conducted by excluding studies with anecdotal or weakly contextualized data, allowing to verify that trends were not disproportionately shaped by a few outliers. All statistical analyses were conducted using Python (v3.10) and R (v4.3.2), and graphical visualizations were generated using the \u003cem\u003eseaborn\u003c/em\u003e, \u003cem\u003ematplotlib\u003c/em\u003e, and \u003cem\u003eggplot2\u003c/em\u003e packages.\u003c/p\u003e\u003cp\u003eTo strengthen the methodological framework and identify hidden patterns in SSB across invertebrate species, an unsupervised machine learning approach was performed, using KMeans clustering combined with Principal Component Analysis (PCA) for dimensionality reduction. This allowed to model latent behavioral groupings based on encoded taxonomic identity, ecological context, and SSB type. Each categorical variable was numerically encoded and subjected to clustering across the multi-dimensional space. The input features included taxonomic group, ecological context (lab, field), and SSB type (copulation, mounting, spermatophore transfer). A three-cluster KMeans model (k\u0026thinsp;=\u0026thinsp;3) was selected based on visual inspection of the PCA distribution and inertia minimization.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eTaxonomic Distribution and Prevalence of SSB\u003c/h2\u003e\u003cp\u003eA total of 219 unique peer-reviewed articles and 12 reviews documenting same-sex sexual behavior (SSB) in 203 invertebrate species. The data covers a wide range of taxa including arthropods (insects, arachnids, crustaceans), mollusks (cephalopods, gastropods), annelids (polychaetes only), echinoderms (sea stars, sea urchins), and other phyla like Acanthocephala (thorny-headed worms), Nematoda, and Platyhelminthes. The publications span from 1895 to 2024, reflecting over a century of academic interest in invertebrate SSB. Within the systematic review, three hypotheses emerged as the most frequently cited to explain the occurrence of same-sex sexual behavior (SSB) in invertebrates: (i) mistaken identity or indiscriminate mating, (ii) social and environmental influences, and (iii) adaptive functions. These explanatory frameworks were present across diverse taxonomic groups (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). For instance, the fruit fly \u003cem\u003eDrosophila melanogaster\u003c/em\u003e and the red flour beetle \u003cem\u003eT. castaneum\u003c/em\u003e each appeared in multiple investigations that linked to different hypotheses to explain SSB, from mistaken identity (Sales et al. \u003cspan citationid=\"CR140\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) to social influence (Martin et al., \u003cspan citationid=\"CR101\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) or indiscriminate mating (Martens et al. \u003cspan citationid=\"CR100\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). These repeated cases were carefully treated to avoid duplication in prevalence metrics, while still considering the variation in hypotheses and results.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eSSB was most frequently reported in insects, which accounted for about 89% of the documented cases in the dataset (195 articles). This was followed by much lower reporting frequencies for mollusks, crustaceans, and arachnids. After normalizing by known species richness, the relative reporting index (RRI) revealed that mega-diverse orders like Hymenoptera and Coleoptera are, in fact, significantly underrepresented in literature (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Conversely, taxa such as Odonata (dragonflies), Cephalopoda (squid), and Cidaroida (pencil urchins) were highly overrepresented. While holometabolous insects had more total reports, certain hemimetabolous groups like Odonata were particularly prominent based on their high RRI. Among other groups, marine invertebrates like polychaetes and arachnids were underrepresented, while rare but notable cases were recorded in phyla such as Acanthocephala and Nematoda.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eA chi-square goodness-of-fit test confirmed that the documented cases were non-randomly distributed across higher taxonomic groups, revealing a highly significant deviation from an equal distribution of reports (χ\u0026sup2; \u0026asymp; 950, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This result is overwhelmingly driven by the massive number of reports in insects compared to all other groups combined. A similar test showed a significant, though less pronounced, association with ecological context, with more reports from the field than from the laboratory (χ\u0026sup2; \u0026asymp; 57.78, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eBehavioral types\u003c/h2\u003e\u003cp\u003eCommon SSB behaviors observed included copulatory attempts or actual genital contact, which was the most frequently documented behavior, appearing in over half the studies and spanning numerous orders including Coleoptera, Diptera, Odonata, and Hemiptera. Courtship displays were also common, particularly in laboratory studies of Diptera, Hymenoptera, and Lepidoptera. Less frequently, mounting was explicitly recorded as a distinct behavior from copulation, alongside pair-bonding or tandem behaviors, which were noted in taxa like Isoptera (termites) and Asteroidea (sea stars). Multiple behavioral types were often recorded within a single order. While complex interactions like pairing were observed in both field (i.e., Asteroidea) and laboratory settings (i.e., Isoptera), many observations of courtship and mounting came from controlled lab studies. The data indicates that cue types vary by taxa; chemical cues such as pheromones and cuticular hydrocarbons were noted as important in insects like Hemiptera and Hymenoptera, while vibrational signals were documented in Hemiptera and chemotactic attraction was noted in Nematoda.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eEcological Context and Experimental Settings\u003c/h3\u003e\n\u003cp\u003eThe ecological context in which behaviors were observed is a key factor, with the majority of reports (approx. 76%) stemming from field observations, while a significant portion (approx. 24%) came from laboratory assays, few studies explicitly combined both contexts. SSB was robustly recorded in natural habitats, while laboratory studies often provided a controlled environment to investigate behaviors with clear ecological relevance, such as the anti-predator tandem running observed in \u003cem\u003eReticulitermes\u003c/em\u003e termites.\u003c/p\u003e\u003cp\u003eThe vast majority of observations were in gonochoric (separate-sexed) species, where male-male interactions such as copulation, mounting, and courtship were the most frequently recorded behaviors across numerous orders. The dataset includes a few examples of hermaphroditic or sex-changing species. In these cases, observed behaviors included male-male courtship (in the shrimp \u003cem\u003eL. wurdemanni\u003c/em\u003e), courtship displays (in the polychaete \u003cem\u003eOphryotrocha diadema\u003c/em\u003e), and hypodermic self-insemination (in the flatworm \u003cem\u003eMacrostomum hystrix\u003c/em\u003e). Notably, the behaviors in some of these listed hermaphroditic species were interpreted as adaptive, such as for reproductive assurance or reducing competition (Baeza and Bauer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eWhere phylogenetic analyses were included, patterns varied. The wide distribution of SSB across disparate phyla and the variety of proposed hypotheses suggest that the behavior's origins are complex, likely involving both lineage-specific predispositions and convergent evolution driven by diverse ecological and social pressures. Pagel\u0026rsquo;s λ indicated strong phylogenetic signal (λ\u0026thinsp;=\u0026thinsp;0.913, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), while Blomberg\u0026rsquo;s K suggested low-to-moderate clustering (K\u0026thinsp;=\u0026thinsp;0.36, p\u0026thinsp;=\u0026thinsp;0.048).\u003c/p\u003e\n\u003ch3\u003eSSB hypotheses testing\u003c/h3\u003e\n\u003cp\u003eThe most frequently cited non-adaptive explanation for SSB was \"mistaken identity,\" which was suggested for numerous species across orders like Coleoptera, Diptera, Hemiptera, and Orthoptera, often attributed to a lack of clear sex-recognition cues. Its simile, \u0026ldquo;Indiscriminate mating\u0026rdquo;, was also frequently cited as explanation for SSB. Nevertheless, various adaptive functions were also proposed. These include SSB as a mechanism to reduce male-male competition (i.e., \u003cem\u003eGnatocerus cornutus\u003c/em\u003e), to practice and enhance future mating success (i.e., \u003cem\u003eP. concolor\u003c/em\u003e), to maximize insemination opportunities in low-visibility environments (i.e., deep-sea squid), or as an anti-predator strategy (i.e., tandem running in \u003cem\u003eReticulitermes\u003c/em\u003e termites). Several studies indicate that high population density increases the frequency of same-sex sexual behavior (SSB). In crowded environments, recognition errors become more likely, and individuals face stronger pressure to mate quickly before losing opportunities. A chi-square test comparing sexual system and the adaptive versus non-adaptive interpretation of behaviors yielded a significant association (χ\u0026sup2; = 4.51, p\u0026thinsp;=\u0026thinsp;0.034). Logistic regression showed that behaviors in species inhabiting high-density or high-risk environments (i.e., termites under threat) were more likely to be interpreted adaptively (z\u0026thinsp;=\u0026thinsp;2.21, p\u0026thinsp;=\u0026thinsp;0.027). While fitness consequences were not systematically reported, specific studies indicated costs (i.e., reduced longevity in the beetle \u003cem\u003eA.s obtectus\u003c/em\u003e), benefits (i.e., the adaptive functions listed above), or neutral effects (i.e., in the flour beetle \u003cem\u003eT. castaneum\u003c/em\u003e).\u003c/p\u003e\u003cp\u003eTo identify latent patterns in the occurrence of same-sex sexual behavior (SSB) across invertebrates, we applied PCA followed by KMeans clustering (k\u0026thinsp;=\u0026thinsp;3). The dataset, which encoded taxonomic affiliation, ecological context (laboratory vs. field), and SSB type (i.e., copulation, mounting, spermatophore transfer), was reduced into two principal components for visualization. The analysis revealed three distinct clusters (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Cluster 1 contained 98 cases, Cluster 2 encompassed 70 cases, and Cluster 0 grouped 52 cases. These clusters were clearly separated in the PCA space, suggesting non-random associations among taxonomy, behavioral form, and ecological setting. Visual inspection indicated that: i) one cluster was enriched in laboratory-based reports of insects, often describing mounting or courtship under artificial density conditions; ii) a second cluster contained field observations of diverse arthropod orders, with copulation being the dominant SSB type; iii) the third cluster appeared to combine more phylogenetically distant taxa (i.e., annelids, mollusks, acanthocephalans), where SSB was typically noted as rare or incidental.\u003c/p\u003e\u003cp\u003eMeta-analysis from N\u0026thinsp;=\u0026thinsp;22 studies reporting fitness data indicated no overall significant effect (Hedges' g\u0026thinsp;=\u0026thinsp;0.103; 95% CI: -0.016 to 0.222), but subgroup analyses suggest context-dependent outcomes. Strong evidence for non-adaptive drivers was found in species with rapid mating dynamics, weak sexual dimorphism, and overlapping chemical profiles. However, even in these cases, behaviors sometimes provided secondary benefits (i.e., stimulation of later heterosexual success), blurring the adaptive versus non-adaptive dichotomy.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eSame-sex sexual behavior was found to be taxonomically widespread and contextually diverse among invertebrates, although unevenly reported. Although previously considered as anomalous or maladaptive, SSB seems to serve functional roles, from reducing predation risk and enhancing mating skills to ensuring reproductive continuity in sex-limited environments. In this sense, SSB may be a form of evolutive behavioral plasticity, responding to ecological, social, or physiological pressures.\u003c/p\u003e\u003cp\u003eThe predominance of insects and flatworms in documented cases mirrors earlier observations (Bailey and Zuk, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Scharf and Martin, \u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), yet our findings reinforce this trend likely reflects research bias rather than true behavioral frequency. Insects are frequently used in behavioral and genetic experiments due to ease of laboratory rearing, while flatworms, particularly the genus \u003cem\u003eMacrostomum\u003c/em\u003e, offer transparent bodies and observable reproductive traits that facilitate experimental observation (Sch\u0026auml;rer et al. 2017).\u003c/p\u003e\u003cp\u003eThe significant chi-square result indicating a non-random taxonomic distribution of SSB reinforces concerns raised by Rivera-Ingraham et al. (2011) and Monk et al. (\u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), who highlighted the neglect of lesser-studied marine and benthic taxa. Our standardized reporting metric helps adjust for research effort but cannot fully disentangle discovery bias from true absence of behavior. Future field surveys in underrepresented clades, such as polychaetes or echinoderms, may reveal a broader spectrum of SSB than is currently acknowledged.\u003c/p\u003e\u003cp\u003eEcological context showed influence on the type and interpretation of SSB. Our results confirm that laboratory environments disproportionately document behaviors such as mounting and courtship, particularly in species like \u003cem\u003eD. melanogaster\u003c/em\u003e and \u003cem\u003eT. castaneum\u003c/em\u003e. While controlled settings allow for standardized comparisons, they may also elicit behaviors that are rare or absent under natural conditions. This artificial inflation of certain behaviors has previously been critiqued (Bailey et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Clancy et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), and our results corroborate those concerns by highlighting a higher frequency of maladaptive interpretations in laboratory studies. Conversely, field-based reports often document SSB behaviors with presumed non-adaptive or environmentally constrained origins, such as mistaken spermatophore implantation in \u003cem\u003eOctopoteuthis deletron\u003c/em\u003e (Hoving and Robison 2012) or tandem pairing in \u003cem\u003eC. splendens\u003c/em\u003e following flooding events (Gołąb and Śniegula \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). These behaviors may result from temporary disruptions in sensory cues, population density, or predator-induced stress, underscoring the need to account for ecological variability when interpreting SSB.\u003c/p\u003e\u003cp\u003eSexual systems seem to shape SSB patterns. Hermaphroditic species such as \u003cem\u003eM. lignano\u003c/em\u003e and \u003cem\u003eL. wurdemanni\u003c/em\u003e frequently engage in reciprocal copulation and show high rates of adaptive interpretations, supporting the idea that flexible sex allocation strategies can promote the evolution of SSB (Sch\u0026auml;rer and Ladurner 2003; Baeza and Bauer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). The chi-square results corroborate that hermaphroditism is significantly associated with adaptive framing of SSB, echoing findings from Ramm et al. (\u003cspan citationid=\"CR131\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), who argued that reproductive assurance, sperm competition, and social learning may all shape these behaviors. In contrast, gonochoric species, particularly insects, often exhibit unilateral SSB behaviors interpreted as mistaken identity, especially in crowded conditions or in the absence of sex-specific cues (Bailey and French \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Sales et al. \u003cspan citationid=\"CR140\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). This aligns with our regression results showing that ecological complexity, more than taxonomy or sexual system alone, predicts the likelihood of an adaptive explanation. These findings provide support for the hypothesis that SSB may emerge as a context-dependent trait modulated by external pressures rather than a fixed behavioral syndrome. In fact, under environmental stress or predator pressure, organisms may reduce the time spent on sexual discrimination, favoring indiscriminate behaviors such as rapid mounting with same-sex partners. Similarly, laboratory conditions, where densities are artificially high and environmental cues are reduced, have also been reported to exacerbate the occurrence of SSB.\u003c/p\u003e\u003cp\u003eThe phylogenetic signal detected by both Pagel\u0026rsquo;s λ and Blomberg\u0026rsquo;s K suggests a strong level of evolutionary conservatism in the presence of SSB, paralleling observations in vertebrate systems (Monk et al. \u003cspan citationid=\"CR111\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This reinforces the conclusion that the occurrence of Same-Sex Behavior (SSB) in invertebrates shows a significant phylogenetic signal, being not randomly scattered across the invertebrate tree of life; instead, clustering within related lineages. The last suggests that both shared ancestry and convergent ecological pressures contribute to the occurrence of SSB. This nuanced view challenges earlier models that treated SSB either as entirely maladaptive (Abele and Gilchrist \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1977\u003c/span\u003e) or solely as a byproduct of indiscriminate mating (Han and Brooks \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Instead, our findings suggest that SSB may represent a flexible evolutionary response shaped by lineage history and immediate social or environmental conditions. However, it must be considered that this analysis is based on reported cases, therefore, the absence of SSB in the 85 control orders is, more accurately, an absence of evidence, not necessarily evidence of absence, reflecting human research effort more than the complete distribution of animal behavior. In fact, some invertebrate groups, like fruit flies, certain beetles, and commercially relevant butterflies, are studied intensively. Their behaviors, including SSB, are well-documented, while countless other orders are cryptic, difficult to culture, live in inaccessible environments or are simply not a focus of research funding. SSB could be common in these groups but entirely unobserved. Still, even with these significant data limitations, the strong phylogenetic signal is still a very meaningful result. Instead of searching randomly, researchers can now target their efforts. Future research should focus on sister groups to the major insect orders with high rates of SSB.\u003c/p\u003e\u003cp\u003eThe unsupervised machine learning analysis provides a novel contribution to the study of animal behavior. The use of KMeans clustering, supported by PCA, revealed three distinct behavioral groupings not fully predicted by taxonomy alone. These clusters reflected: i) experimentally tractable species showing copulatory behaviors under artificial conditions, ii) adaptive reciprocators such as hermaphrodites, and iii) naturally observed species with low-frequency or error-driven behaviors. This typology aligns with frameworks proposed by Scharf and Martin (\u003cspan citationid=\"CR142\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) and Lane et al. (\u003cspan citationid=\"CR91\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) but provides a data-driven method for classification. The integration of artificial intelligence tools into behavioral ecology is still at an early stage. However, our results show that even basic unsupervised models can uncover meaningful patterns that enhance or even challenge expert-based classifications. Future studies could employ neural networks or ensemble models incorporating ethological metadata to refine predictions of when and where SSB is likely to evolve. This approach has the potential to revolutionize comparative behavior studies by increasing objectivity and expanding analytical scalability.\u003c/p\u003e\u003cp\u003eAlthough non-adaptive hypotheses such as mistaken identity or indiscriminate mating have often been invoked to explain SSB, these mechanisms may themselves represent adaptive strategies. In certain contexts, the benefit of attempting to mate with a conspecific may exceed the costs of a misidentification, as has been proposed by Han and Brook (2015) and Gavrilets and Rice (2015). This perspective helps to explain why same-sex interactions are observed across such a wide diversity of invertebrate taxa, despite the potential fitness costs associated with injuries, wasted gametes, or reduced longevity. By reducing the risk of lost reproductive chances, these behaviors may provide a selective advantage that contributes to their persistence across evolutionary lineages.\u003c/p\u003e\u003cp\u003eThis study provides a comprehensive quantitative synthesis to date of SSB in invertebrates, spanning over four decades of research and applying both classical statistics and machine learning. In doing so, it helps bridge persistent gaps in our understanding of how sexual behavior evolves outside the vertebrate-centric framework. Our results support the growing consensus that SSB is not inherently maladaptive but may arise through diverse, often context-specific mechanisms (Bailey and Zuk, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Mizumoto et al., \u003cspan citationid=\"CR110\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Moreover, the findings reinforce the need for more inclusive and ecologically realistic studies of animal sexual behavior. With invertebrates comprising most of the animal diversity, continued neglect of these taxa limits the scope of evolutionary theory itself.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cem\u003eFunding declaration\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThis study was funded by the Programa\u0026nbsp;de Apoyo a la Instalaci\u0026oacute;n en Investigaci\u0026oacute;n\u0026nbsp;PA_INST_2025_25 to VPO, and by the ANID Scholarship Program 2023-21230929 to CMM.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCompeting interests\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSignificance Statement\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eSame-sex sexual behavior (SSB) has traditionally been viewed as anomalous or maladaptive. Our systematic synthesis across more than 200 invertebrate species demonstrates that SSB is taxonomically widespread and strongly influenced by ecological and social contexts. By integrating statistical analyses, phylogenetic signal tests, and machine learning clustering, we reveal that SSB seems to not be a random occurrence but a structured and context-dependent aspect of reproductive strategies. Evidence shows both adaptive and non-adaptive components, including benefits such as reproductive assurance, predator avoidance, and enhanced mating competence, alongside potential costs like reduced longevity. These findings underscore that SSB is not merely a byproduct of recognition errors but can serve meaningful evolutionary functions. By expanding the empirical and theoretical framework to include invertebrates, this study contributes to a broader, more inclusive understanding of sexual behavior and its evolutionary significance.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eData availability statement\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article and in the supplementary materials.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAuthor contributions\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eVPO: concept and writing of the first draft, plus the main analyses. VPO and CMM: final writing. All authors reviewed and edited the manuscript and agreed on the final version.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEthics approval statement\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eFormal ethics approval was not necessary for this study.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePermission to reproduce material from other sources\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eNo permissions were required for this work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbele LG, Gilchrist S (1977) Homosexual rape and sexual selection in Acanthocephalan Worms. Science 197:81\u0026ndash;83. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1126/science.867055\u003c/span\u003e\u003cspan address=\"10.1126/science.867055\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAiken RB (1981) The Relationship between Body Weight and Homosexual Mounting in \u003cem\u003ePalmacorixa nana\u003c/em\u003e Walley (Heteroptera: Corixidae). Fla Entomol 64:267. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2307/3494579\u003c/span\u003e\u003cspan address=\"10.2307/3494579\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlcock J (1996) Male mate-locating behavior in two Australian butterflies, \u003cem\u003eAnaphaeis java teutonia\u003c/em\u003e (Fabricius) (Pieridae) and \u003cem\u003eAcraea andromacha andromacha\u003c/em\u003e (Fabricius) (Nymphalidae). J Res Lepid 32:1\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.5962/p.280589\u003c/span\u003e\u003cspan address=\"10.5962/p.280589\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlcock J, Buchmann SL (1985) The Significance of Post\u0026ndash;insemination Display by Male \u003cem\u003eCentris pallida\u003c/em\u003e (Hymenoptera: Anthophoridae). Z Tierpsychol 68:231\u0026ndash;243. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1439-0310.1985.tb00126.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1439-0310.1985.tb00126.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlexander RD (1961) Aggressiveness, Territoriality, and Sexual Behavior in Field Crickets (Orthoptera: Gryllidae). Behaviour 17:130\u0026ndash;223\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAllsopp PG, Morgan TA (1991) Male-male copulation in \u003cem\u003eAntitrogus consanguineus\u003c/em\u003e (Blackburn) (Coleoptera: Scarabaeidae). Aust J Enomol 18(4):147\u0026ndash;148\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAmbrogio OV, Pechenik JA (2008) When is a male not a male? Sex recognition and choice in two sex-changing species. Behav Ecol Sociobiol 62:1779\u0026ndash;1786. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00265-008-0606-4\u003c/span\u003e\u003cspan address=\"10.1007/s00265-008-0606-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnderson JR, Nilssen AC, Folstad I (1994) Mating behavior and thermoregulation of the reindeer warble fly, \u003cem\u003eHypoderma tarandi\u003c/em\u003e L. (Diptera: Oestridae). J Insect Behav 7:679\u0026ndash;706. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF01997439\u003c/span\u003e\u003cspan address=\"10.1007/BF01997439\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eArcher CR, Hosken DJ (2024) Resolving the puzzle of same-sex sexual interactions. Nat Rev Urol 21(4):195\u0026ndash;196\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eArita LH, Kaneshiro KY (1989) Pseudomale Courtship Behavior of the Female Mediterranean Fruit Fly, \u003cem\u003eCeratitis capitata\u003c/em\u003e (Wiedemann). Pac Sci 43:2\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAvosani S, Sullivan TE, Ciolli M et al (2020) Can Vibrational Playbacks Disrupt Mating or Influence Other Relevant Behaviours in \u003cem\u003eBactericera cockerelli\u003c/em\u003e (Triozidae: Hemiptera)? Insects 11:299. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/insects11050299\u003c/span\u003e\u003cspan address=\"10.3390/insects11050299\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBaeza JA, Bauer RT (2004) Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite, the marine shrimp \u003cem\u003eLysmata wurdemanni\u003c/em\u003e (Caridea: Hippolytidae). Behav Ecol Sociobiol 55(6):544\u0026ndash;550. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00265-003-0744-7\u003c/span\u003e\u003cspan address=\"10.1007/s00265-003-0744-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBagemihl B (1999) Biological exuberance: Animal homosexuality and natural diversity. Macmillan, St. Martin's\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBailey NW, Zuk M (2009) Same-sex sexual behavior and evolution. Trends Ecol Evol 24(8):439\u0026ndash;446. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.tree.2009.03.014\u003c/span\u003e\u003cspan address=\"10.1016/j.tree.2009.03.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBailey NW, French N (2012) Same-sex sexual behaviour and mistaken identity in male field crickets, \u003cem\u003eTeleogryllus oceanicus\u003c/em\u003e. Anim Behav 84:1031\u0026ndash;1038. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2012.08.001\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2012.08.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBailey NW, Hoskins JL, Green J, Ritchie MG (2013) Measuring same-sex sexual behaviour: the influence of the male social environment. Anim Behav 86:91\u0026ndash;100. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2013.04.016\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2013.04.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBalfour VL, Shuker DM (2020) Same-sex sexual behaviour. Curr Biol 30(22):R1345\u0026ndash;R1346. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.cub.2020.09.005\u003c/span\u003e\u003cspan address=\"10.1016/j.cub.2020.09.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBarrows EM, Gordh G (1978) Sexual behavior in the Japanese beetle, Popillia japonica, and comparative notes on sexual behavior of other scarabs (Coleoptera: Scarabaeidae). Behav Biol 23:341\u0026ndash;354. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0091-6773(78)91365-2\u003c/span\u003e\u003cspan address=\"10.1016/S0091-6773(78)91365-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBarth RH (1964) The Mating Behavior of \u003cem\u003eByrsotria fumigata\u003c/em\u003e (Gu\u0026eacute;rin) (Blattidae, Blaberinae). Behaviour 23:1\u0026ndash;30\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBauer RT, Baeza JA (2004) Experimental test of socially mediated sex change in a protandric simultaneous hermaphrodite, the marine shrimp \u003cem\u003eLysmata wurdemanni\u003c/em\u003e (Caridea: Hippolytidae). Behav Ecol Sociobiol 55:544\u0026ndash;550. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00265-003-0744-7\u003c/span\u003e\u003cspan address=\"10.1007/s00265-003-0744-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Canale A (2012) Do \u003cem\u003ePsyttalia concolor\u003c/em\u003e (Hymenoptera: Braconidae) males gain in mating competitiveness from being courted by other males while still. young? Entomol Sci 15:257\u0026ndash;260. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1479-8298.2011.00503.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1479-8298.2011.00503.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Canale A (2013) Male-male sexual behavior in the parasitic wasp \u003cem\u003ePsyttalia concolor\u003c/em\u003e. J Insect Sci 13(1):25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1673/031.013.2501\u003c/span\u003e\u003cspan address=\"10.1673/031.013.2501\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Giunti G, Messing RH, Wright MG (2013a) Visual and Olfactory Female-Borne Cues Evoke Male Courtship in the Aphid Parasitoid \u003cem\u003eAphidius colemani\u003c/em\u003e Viereck (Hymenoptera: Braconidae). J Insect Behav 26:695\u0026ndash;707. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10905-013-9386-4\u003c/span\u003e\u003cspan address=\"10.1007/s10905-013-9386-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Gennari G, Francini A, Canale A (2013b) Longevity costs of same-sex interactions: first evidence from a parasitic wasp. Invertebr Biol 132:156\u0026ndash;162. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/ivb.12017\u003c/span\u003e\u003cspan address=\"10.1111/ivb.12017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Meregalli M, Canale A (2014a) Field Observations on the Mating Behavior of Aclees sp. cf. foveatus Voss (Coleoptera: Curculionidae), an Exotic Pest Noxious to Fig Orchards. J Insect Behav 27:419\u0026ndash;427. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10905-014-9437-5\u003c/span\u003e\u003cspan address=\"10.1007/s10905-014-9437-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Bonsignori G, Stefanini C, Raspi A (2014b) First Quantification of Courtship Behavior in a Silver Fly, \u003cem\u003eLeucopis palumbii\u003c/em\u003e (Diptera: Chamaemyiidae): Role of Visual, Olfactory and Tactile Cues. J Insect Behav 27:462\u0026ndash;477. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10905-014-9443-7\u003c/span\u003e\u003cspan address=\"10.1007/s10905-014-9443-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenelli G, Messing RH, Wright MG et al (2014c) Cues Triggering Mating and Host-Seeking Behavior in the Aphid Parasitoid \u003cem\u003eAphidius colemani\u003c/em\u003e (Hymenoptera: Braconidae: Aphidiinae): Implications for Biological Control. J Econ Entomol 107:2005\u0026ndash;2022. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1603/EC14291\u003c/span\u003e\u003cspan address=\"10.1603/EC14291\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBennett G (1974) Mating behavior of the rosechafer in northern Michigan (Coleoptera: Scarabaeidae). Coleopt Bull 167\u0026ndash;168\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenz G (1973) Role of sex pheromone, and its insignificance for heterosexual and homosexual behaviour of larch bud moth. Experientia 29(5):553\u0026ndash;554\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBerger D, You T, Minano MR et al (2016) Sexually antagonistic selection on genetic variation underlying both male and female same-sex sexual behavior. BMC Evol Biol 16:88. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12862-016-0658-4\u003c/span\u003e\u003cspan address=\"10.1186/s12862-016-0658-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBerlese A (1909) Gli insetti: loro organizzazione, sviluppo, abitudini e rapporti coll'uomo, vol 1. Societa Editrice Libraria\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBickel DJ, Dyte CE (1989) Family Dolichopodidae. In: Evenhuis N (ed) A catalog of the Diptera of the Australasian and Oceanian region. Honolulu, Bishop Museum Press and E.J. Brill, p 1155\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBologna M, Marangoni C (1986) Sexual behaviour in some palaearctic species of \u003cem\u003eMeloe\u003c/em\u003e (Coleoptera Meloidae). Bollettino della Societ\u0026agrave;. Entomologica Italiana 118:65\u0026ndash;82\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBoutin SRT, Harrison SJ, Fitzsimmons LP et al (2016) Same-sex sexual behaviour in crickets: understanding the paradox. Anim Behav 114:101\u0026ndash;110. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2016.01.022\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2016.01.022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBristowe WS (1929) The Mating Habits of Spiders, with special reference to the Problems surrounding Sex Dimorphisn. Proc Zool Soc Lond 99(2):309\u0026ndash;358\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBrower LP (1965) Courtship behavior of the queen butterfly, \u003cem\u003eDanaus gilippus berenice\u003c/em\u003e (Cramer). Zoologica 50:1\u0026ndash;39\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBurgevin L, Friberg U, Maklakov AA (2013) Intersexual correlation for same-sex sexual behaviour in an insect. Anim Behav 85:759\u0026ndash;762. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2013.01.017\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2013.01.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCaballero-Mendieta N, Cordero C (2012) Enigmatic Liaisons in Lepidoptera: A Review of Same-Sex Courtship and Copulation in Butterflies and Moths. J Insect Sci 12:1\u0026ndash;11. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1673/031.012.13801\u003c/span\u003e\u003cspan address=\"10.1673/031.012.13801\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCane JH (1994) Nesting Biology and Mating Behavior of the Southeastern Blueberry Bee, \u003cem\u003eHabropoda laboriosa\u003c/em\u003e (Hymenoptera: Apoidea). J Kans Entomol Soc 67:236\u0026ndash;241\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarayon J (1966) Traumatic Insemination and the Paragenital System. Monograph of Cimicidae (Hemiptera-Heteroptera). Entomological Society of America, p 81\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCastro L, Toro MA, L\u0026oacute;pez-Fanjul C (1994) The genetic properties of homosexual copulation behaviour in \u003cem\u003eTribolium castaneum\u003c/em\u003e: artificial selection. Genet Sel Evol 26(4):361\u0026ndash;367\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChaudhuri A, Sinha AK (1994) Colleterectomy and its impact on some reproductive behaviour of the tropical Tasar silk moth, \u003cem\u003eAntheraea mylitta\u003c/em\u003e Drury (Lepidoptera: Saturniidae). IRD 26(2): 145\u0026ndash;152\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChin DA, Taylor DP (1969) Sexual Attraction and Mating Patterns in \u003cem\u003eCylindrocorpus longistoma\u003c/em\u003e and \u003cem\u003eC. curzii\u003c/em\u003e (Nematoda: Cylindrocorporidae). J Nematol 1(4):313\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eClancy LM, Cooper AL, Griffith GW, Santer RD (2017) Increased Male-Male Mounting Behaviour in Desert Locusts during Infection with an Entomopathogenic Fungus. Sci Rep 7:5659. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-017-05800-4\u003c/span\u003e\u003cspan address=\"10.1038/s41598-017-05800-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eConstantz GD (1974) The Mating Behavior of a Creeping Water Bug, \u003cem\u003eAmbrysus occidentalis\u003c/em\u003e (Hemiptera: Naucoridae). Am Midl Nat 92:234. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2307/2424220\u003c/span\u003e\u003cspan address=\"10.2307/2424220\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCostanzo K, Monteiro A (2007) The use of chemical and visual cues in female choice in the butterfly \u003cem\u003eBicyclus anynana\u003c/em\u003e. Proc R Soc B 274:845\u0026ndash;851. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2006.3729\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2006.3729\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDavid WAL, Gardiner BOC (1961) The mating behaviour of \u003cem\u003ePieris brassicae\u003c/em\u003e (L.) in a laboratory culture. Bull Entomol Res 52:263\u0026ndash;280. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1017/S0007485300055401\u003c/span\u003e\u003cspan address=\"10.1017/S0007485300055401\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDukas R (2010) Causes and consequences of male\u0026ndash;male courtship in fruit flies. Anim Behav 80:913\u0026ndash;919. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2010.08.017\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2010.08.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDunkle SW (1991) Head damage from mating attempts in dragonflies (Odonata: Anisoptera). Entomol News 102(1):37\u0026ndash;41\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEisenhauer N, Hines J (2021) Invertebrate biodiversity and conservation. Curr Biol 31(19):R1214\u0026ndash;R1218\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eElgar MA, Pierce (1988) Mating Success and Fecundity in an Ant-Tended Lycaenid Butterfly. Reproductive success: studies of selection and adaptation in contrasting breeding systems, 59\u0026ndash;75\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEngel KC, M\u0026auml;nner L, Ayasse M, Steiger S (2015) Acceptance threshold theory can explain occurrence of homosexual behaviour. Biol Lett 11:20140603. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rsbl.2014.0603\u003c/span\u003e\u003cspan address=\"10.1098/rsbl.2014.0603\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEstrada C, Yildizhan S, Schulz S, Gilbert LE (2010) Sex-specific chemical cues from immatures facilitate the evolution of mate guarding in \u003cem\u003eHeliconius\u003c/em\u003e butterflies. Proc R Soc B 277:407\u0026ndash;413. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2009.1476\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2009.1476\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFianco M, Prasniewski VM (2018) Ethology of the cricket \u003cem\u003eEndecous\u003c/em\u003e (\u003cem\u003eEndecous\u003c/em\u003e) chape Souza-Dias \u0026amp; de Mello, 2017 (Orthoptera: Grylloidea: Phalangopsidae) I: Agonistic and reproductive behavior. JOR 27(2): 193\u0026ndash;201\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eField SA, Keller MA (1993) Courtship and intersexual signaling in the parasitic wasp (Hymenoptera: Braconidae). J Insect Behav 6:737\u0026ndash;750. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF01201673\u003c/span\u003e\u003cspan address=\"10.1007/BF01201673\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFinley KD, Taylor BJ, Milstein M, McKeown M (1997) \u003cem\u003edissatisfaction\u003c/em\u003e, a gene involved in sex-specific behavior and neural development of \u003cem\u003eDrosophila melanogaster\u003c/em\u003e. Proc Natl Acad Sci USA 94:913\u0026ndash;918. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1073/pnas.94.3.913\u003c/span\u003e\u003cspan address=\"10.1073/pnas.94.3.913\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFletcher LW, O\u0026rsquo;Grady JJ, Claborn HV, Graham OH (1966) A Pheromone from Male Screw-Worm Flies. J Econ Entomol 59:142\u0026ndash;143. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/jee/59.1.142\u003c/span\u003e\u003cspan address=\"10.1093/jee/59.1.142\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eForsyth A, Alcock J (1990) Female mimicry and resource defense polygyny by males of a tropical rove beetle, \u003cem\u003eLeistotrophus versicolor\u003c/em\u003e (Coleoptera: Staphylinidae). Behav Ecol Sociobiol 26. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF00171097\u003c/span\u003e\u003cspan address=\"10.1007/BF00171097\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Gadeau H (1896) Perversion sexuelle chez des Col\u0026eacute;opt\u0026egrave;res m\u0026acirc;les. Bsef 1:85\u0026ndash;87. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3406/bsef.1896.28506\u003c/span\u003e\u003cspan address=\"10.3406/bsef.1896.28506\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGillespie RG (1991) Homosexual mating behavior in male \u003cem\u003eDoryonychus raptor\u003c/em\u003e (Araneae, Tetragnathidae). JoA 19(3):229\u0026ndash;230\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGiunti G, Campolo O, Laudani F, Palmeri V (2018) Male courtship behaviour and potential for female mate choice in the black soldier fly \u003cem\u003eHermetia illucens\u003c/em\u003e L. (Diptera: Stratiomyidae). Entomol Gen 38(1):29\u0026ndash;46\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGołąb MJ, Śniegula S (2012) Changes in reproductive behavior in adult damselfly \u003cem\u003eCalopteryx splendens\u003c/em\u003e (Odonata: Calopterygidae) in response to flood. Entomol Sci 15:280\u0026ndash;287. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1479-8298.2012.00516.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1479-8298.2012.00516.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHafernik JE (1982) Phenetics and ecology of hybridization in buckeye butterflies (Lepidoptera: Nymphalidae), vol 96. Univ of California\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHall DR, Cork A, Lester R, Zagatti P (1987) Sex pheromones of rice moth, \u003cem\u003eCorcyra cephalonica\u003c/em\u003e Stainton. J Chem Ecol 13:1561\u0026ndash;1573. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF00980200\u003c/span\u003e\u003cspan address=\"10.1007/BF00980200\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHan CS, Brooks RC (2015) Same-sex sexual behaviour as a by-product of reproductive strategy under male\u0026ndash;male scramble competition. Anim Behav 108:193\u0026ndash;197. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2015.07.035\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2015.07.035\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHan CS, Santostefano F, Dingemanse NJ (2016) Do social partners affect same-sex sexual behaviour in male water striders? Anim Behav 116:53\u0026ndash;59. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2016.03.033\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2016.03.033\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHanks LM, Millar JG, Paine TD (1996) Mating behavior of the eucalyptus longhorned borer (Coleoptera: Cerambycidae) and the adaptive significance of long horns. J Insect Behav 9:383\u0026ndash;393. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF02214017\u003c/span\u003e\u003cspan address=\"10.1007/BF02214017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHarari AR, Brockmann HJ (1999) Male beetles attracted by females mounting. Nature 401:762\u0026ndash;763. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/44515\u003c/span\u003e\u003cspan address=\"10.1038/44515\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHarari AR, Brockmann HJ, Landolt PJ (2000) Intrasexual mounting in the beetle \u003cem\u003eDiaprepes abbreviatus\u003c/em\u003e (L). Proc R Soc Lond B 267:2071\u0026ndash;2079. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2000.1251\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2000.1251\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHarris VE, Todd JW (1980) Temporal and numerical patterns of reproductive behavior in the southern green stink bug, \u003cem\u003eNezara viridula\u003c/em\u003e (hemiptera: pentatomidae). Entomol Exp Appl 27:105\u0026ndash;116. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1570-7458.1980.tb02954.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1570-7458.1980.tb02954.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHayes WP (1927) Congeneric and intergeneric pederasty in the Scarabaeidae (Coleop). Entomol News 38:216\u0026ndash;218\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHay-Roe MM, Lamas G, Nation JL (2007) Pre- and postzygotic isolation and Haldane rule effects in reciprocal crosses of \u003cem\u003eDanaus erippus\u003c/em\u003e and \u003cem\u003eDanaus plexippus\u003c/em\u003e (Lepidoptera: Danainae), supported by differentiation of cuticular hydrocarbons, establish their status as separate species: pre- and postzygotic isolation and haldane rule effects. Biol J Linn Soc 91:445\u0026ndash;453. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1095-8312.2007.00809.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1095-8312.2007.00809.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHe XZ (2008) Reproductive Behaviour of Aphidius \u003cem\u003eErvi Haliday\u003c/em\u003e (Hymenoptera: Aphidiidae). Dissertation, Massey University, Palmerston North, New Zealand\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeatwole H, Davis DM, Wenner AM (2010) The Behaviour of \u003cem\u003eMegarhyssa\u003c/em\u003e, a Genus of Parasitic Hymenopterans (Ichneumonidae: Ephialtinae)1. Z Tierpsychol 19:652\u0026ndash;664. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1439-0310.1962.tb00796.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1439-0310.1962.tb00796.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHenry CS (1979) Acoustical Communication during Courtship and Mating in the Green Lacewing \u003cem\u003eChrysopa carnea\u003c/em\u003e (Neuroptera: Chrysopidae). Ann Entomol Soc Am 72:68\u0026ndash;79. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/aesa/72.1.68\u003c/span\u003e\u003cspan address=\"10.1093/aesa/72.1.68\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHoskins JL, Ritchie MG, Bailey NW (2015) A test of genetic models for the evolutionary maintenance of same-sex sexual behaviour. Proc R Soc B 282:20150429. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2015.0429\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2015.0429\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHoving HJT, Bush SL, Robison BH (2012) A shot in the dark: same-sex sexual behaviour in a deep-sea squid. Biol Lett 8:287\u0026ndash;290. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rsbl.2011.0680\u003c/span\u003e\u003cspan address=\"10.1098/rsbl.2011.0680\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHoving H-JT, Fern\u0026aacute;ndez-\u0026Aacute;lvarez F\u0026Aacute;, Portner EJ, Gilly WF (2019) Same-sex sexual behaviour in an oceanic ommastrephid squid, \u003cem\u003eDosidicus gigas\u003c/em\u003e (Humboldt squid). Mar Biol 166:33. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00227-019-3476-6\u003c/span\u003e\u003cspan address=\"10.1007/s00227-019-3476-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHumphries DA (1967) The mating behaviour of the hen flea \u003cem\u003eCeratophyllus gallinae\u003c/em\u003e (Schrank) (Siphonaptera: Insecta). Anim Behav 15:82\u0026ndash;90. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0003-3472(67)80016-2\u003c/span\u003e\u003cspan address=\"10.1016/S0003-3472(67)80016-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIsa M, Kumano N, Tatsuta H (2019) When a male perceives a female: the effect of waxy components on the body surface on decision-making in the invasive pest weevil. R Soc open sci 6:181542. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rsos.181542\u003c/span\u003e\u003cspan address=\"10.1098/rsos.181542\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIwabuchi K (1988) Mating behavior of \u003cem\u003eXylotrechus pyrrhoderus\u003c/em\u003e Bates (Coleoptera: Cerambycidae). VI mating system. J Ethol 6:69\u0026ndash;76. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF02350870\u003c/span\u003e\u003cspan address=\"10.1007/BF02350870\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJackson RR (1982) The biology of Portia fimbriata, a web-building jumping spider (Araneae, Salticidae) from Queensland: intraspecific interactions. J Zool 196:295\u0026ndash;305. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1469-7998.1982.tb03505.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1469-7998.1982.tb03505.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJiggins FM, Hurst GDD, Majerus MEN (2000) Sex-ratio-distorting \u003cem\u003eWolbachia\u003c/em\u003e causes sex-role reversal in its butterfly host. Proc R Soc Lond B 267:69\u0026ndash;73. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2000.0968\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2000.0968\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKant R, Minor MA, Trewick SA (2012) Reproductive strategies of \u003cem\u003eDiaeretiella rapae\u003c/em\u003e (Hymenoptera: Aphidiinae) during fluctuating temperatures of spring season in New Zealand. Biocontrol Sci Technol 22:1\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/09583157.2011.635248\u003c/span\u003e\u003cspan address=\"10.1080/09583157.2011.635248\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKazmi QB, Tirmizi NM (1987) An unusual behaviour in box crabs (Decapoda, Brachyura, Calappidae). Crustaceana 53(3):313\u0026ndash;314\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKeesing JK, Graham F, Irvine TR, Crossing R (2011) Synchronous aggregated pseudo-copulation of the sea star \u003cem\u003eArchaster angulatus\u003c/em\u003e M\u0026uuml;ller \u0026amp; Troschel, 1842 (Echinodermata: Asteroidea) and its reproductive cycle in south-western Australia. Mar Biol 158:1163\u0026ndash;1173. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00227-011-1638-2\u003c/span\u003e\u003cspan address=\"10.1007/s00227-011-1638-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKobayashi M, Furuya H, Holland PWH (1999) Dicyemids are higher animals. Nature 401:762\u0026ndash;762. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/44513\u003c/span\u003e\u003cspan address=\"10.1038/44513\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKotyk M, Varad\u0026iacute;nov\u0026aacute; Z (2017) Wing reduction influences male mating success but not female fitness in cockroaches. Sci Rep 7:2367. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-017-02647-7\u003c/span\u003e\u003cspan address=\"10.1038/s41598-017-02647-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKuenen LPS, Baker TC (1983) A non-anemotactic mechanism used in pheromone source location by flying moths. Physiol Entomol 8(3):277\u0026ndash;289\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKuriwada T (2017) Male\u0026ndash;male courtship behaviour, not relatedness, affects the intensity of contest competition in the field cricket. Anim Behav 126:217\u0026ndash;220. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2017.02.009\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2017.02.009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLane SM, Haughan AE, Evans D et al (2016) Same-sex sexual behaviour as a dominance display. Anim Behav 114:113\u0026ndash;118. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2016.01.005\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2016.01.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLeCato GL, Pienkowski RL (1970) Laboratory Mating Behavior of the Alfalfa Weevil, \u003cem\u003eHypera postica\u003c/em\u003e. Ann Entomol Soc Am 63:1000\u0026ndash;1007. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/aesa/63.4.1000\u003c/span\u003e\u003cspan address=\"10.1093/aesa/63.4.1000\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLecomte C, Thibout E, Pierre D, Auger J (1998) Transfer, perception, and activity of male pheromone of \u003cem\u003eAcrolepiopsis assectella\u003c/em\u003e with special reference to conspecific male sexual inhibition. J Chem Ecol 24(4):655\u0026ndash;671. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1023/A:1022390102631\u003c/span\u003e\u003cspan address=\"10.1023/A:1022390102631\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLerch BA, Servedio MR (2021) Same-sex sexual behaviour and selection for indiscriminate mating. Nat Ecol Evol 5(1):135\u0026ndash;141. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41559-020-01331-w\u003c/span\u003e\u003cspan address=\"10.1038/s41559-020-01331-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi G, Zou X, Lei C, Huang Q (2013) Antipredator Behavior Produced by Heterosexual and Homosexual Tandem Running in the Termite \u003cem\u003eReticulitermes chinensis\u003c/em\u003e (Isoptera: Rhinotermitidae). Sociobiology 60:198\u0026ndash;203. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.13102/sociobiology.v60i2.198-203\u003c/span\u003e\u003cspan address=\"10.13102/sociobiology.v60i2.198-203\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLoher W, Gordon HT (1968) The Maturation of Sexual Behavior in a New Strain of the Large Milkweed Bug, \u003cem\u003eOncopeltus fasciatus\u003c/em\u003e;1. Ann Entomol Soc Am 61:1566\u0026ndash;1572. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/aesa/61.6.1566\u003c/span\u003e\u003cspan address=\"10.1093/aesa/61.6.1566\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLorenzi MC, Araguas A, Bocquet C et al (2019) Courtship behavior as a war of attrition in a simultaneous hermaphrodite. Anim Biol 69:47\u0026ndash;62. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1163/15707563-00001050\u003c/span\u003e\u003cspan address=\"10.1163/15707563-00001050\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLutz RA, Voight JR (1994) Close encounter in the deep. Nature 371(6498):563\u0026ndash;563\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMacchiano A, Razik I, Sagot M (2018) Same-sex courtship behaviors in male-biased populations: evidence for the mistaken identity hypothesis. Acta Ethol 21:147\u0026ndash;151. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10211-018-0293-8\u003c/span\u003e\u003cspan address=\"10.1007/s10211-018-0293-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartens BM, Martin OY, Janicke T, Winkler L (2024) No fitness effects of same-sex copulations in male red flour beetles. Ecol Evol 14:e11027. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/ece3.11027\u003c/span\u003e\u003cspan address=\"10.1002/ece3.11027\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartin CM, Kruse KC, Switzer PV (2015) Social Experience Affects Same-Sex Pairing Behavior in Male Red Flour Beetles (\u003cem\u003eTribolium castaneum\u003c/em\u003e Herbst). J Insect Behav 28:268\u0026ndash;279. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10905-015-9498-0\u003c/span\u003e\u003cspan address=\"10.1007/s10905-015-9498-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMathieu JM (1969) Mating behavior of five species of lucanidae (coleoptera: insecta). Can Entomol 101:1054\u0026ndash;1062. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4039/Ent1011054-10\u003c/span\u003e\u003cspan address=\"10.4039/Ent1011054-10\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMatsuura K, Kuno E, Nishida T (2002) Homosexual Tandem Running as Selfish Herd in \u003cem\u003eReticulitermes speratus\u003c/em\u003e: Novel Antipredatory Behavior in Termites. J Theor Biol 214:63\u0026ndash;70. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1006/jtbi.2001.2447\u003c/span\u003e\u003cspan address=\"10.1006/jtbi.2001.2447\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMatsuura K, Nishida T (2001) Comparison of colony foundation success between sexual pairs and female asexual units in the termite \u003cem\u003eReticulitermes speratus\u003c/em\u003e (Isoptera: Rhinotermitidae). Popul Ecol 43:119\u0026ndash;124. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/PL00012022\u003c/span\u003e\u003cspan address=\"10.1007/PL00012022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMatthiesen FA (1990) Sexual behaviour and other biological aspects of the wild cockroach, \u003cem\u003ePetasodes dominicana\u003c/em\u003e Burmeister, 1839 (Dictyoptera, Blaberidae, Blaberinae). Rev Bras Entomol 34(2):261\u0026ndash;266\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcCarthy D, Young C (2002) Gametogenesis and reproductive behavior in the echinoid Lytechinus variegatus. Mar Ecol Prog Ser 233:157\u0026ndash;168. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3354/meps233157\u003c/span\u003e\u003cspan address=\"10.3354/meps233157\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMitchem LD, Debray R, Formica VA, Brodie ED (2019) Contest interactions and outcomes: relative body size and aggression independently predict contest status. Anim Behav 157:43\u0026ndash;49. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2019.06.031\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2019.06.031\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMizumoto N, Lee S-B, Chouvenc T (2024) The strength of sexual signals predicts same-sex pairing in two \u003cem\u003eCoptotermes\u003c/em\u003e termites. Behav Ecol 35:arae067. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/beheco/arae067\u003c/span\u003e\u003cspan address=\"10.1093/beheco/arae067\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMizumoto N, Bourguignon T, Bailey NW (2022) Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behavior. PNAS 119(46):e2212401119. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1073/pnas.2212401119\u003c/span\u003e\u003cspan address=\"10.1073/pnas.2212401119\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMizumoto N, Yashiro T, Matsuura K (2016) Male same-sex pairing as an adaptive strategy for future reproduction in termites. Anim Behav 119:179\u0026ndash;187. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2016.07.007\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2016.07.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMonk JD, Giglio E, Kamath A, Lambert MR, McDonough CE (2019) An alternative hypothesis for the evolution of same-sex sexual behaviour in animals. Nat Ecol Evol 3(12):1622\u0026ndash;1631. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41559-019-1019-7\u003c/span\u003e\u003cspan address=\"10.1038/s41559-019-1019-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMustafa SG, Spooner-Hart R, Duncan M et al (2015) Age and aggregation trigger mating behaviour in the small hive beetle, \u003cem\u003eAethina tumida\u003c/em\u003e (Nitidulidae). Sci Nat 102:49. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00114-015-1300-9\u003c/span\u003e\u003cspan address=\"10.1007/s00114-015-1300-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakamura H (1969) Comparative studies on the mating behaviour of two species of \u003cem\u003eCallosobruchus\u003c/em\u003e (Coleoptera: Bruchidae). Jpn J Ecol 19:20\u0026ndash;26\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNoble LM, Chang AS, McNelis D et al (2015) Natural Variation in plep-1 Causes Male-Male Copulatory Behavior in \u003cem\u003eC. elegans\u003c/em\u003e. Curr Biol 25:2730\u0026ndash;2737. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.cub.2015.09.019\u003c/span\u003e\u003cspan address=\"10.1016/j.cub.2015.09.019\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNoel P (1895) Accouplements anormaux chez les insectes. Misc Entomol 1:114\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eN\u0026oacute;brega RL, Maia ACD, Lima CHMD et al (2022) Behavioral traits and sexual recognition: multiple signaling in the reproductive behavior of \u003cem\u003eCyclocephala distincta\u003c/em\u003e (Melolonthidae, Cyclocephalini). Acad Bras Ci\u0026ecirc;nc 94:e20200694. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1590/0001-3765202220200694\u003c/span\u003e\u003cspan address=\"10.1590/0001-3765202220200694\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eObara Y, Majerus MEN (2000) Initial Mate Recognition in the British Cabbage Butterfly, \u003cem\u003ePieris rapae rapae\u003c/em\u003e. Zool Sci 17:725\u0026ndash;730. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2108/zsj.17.725\u003c/span\u003e\u003cspan address=\"10.2108/zsj.17.725\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOdendaal FJ, Turchin P, Stermitz FR (1989) Influence of host-plant density and male harassment on the distribution of female \u003cem\u003eEuphydryas anicia\u003c/em\u003e (Nymphalidae). Oecologia 78:283\u0026ndash;288. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF00377167\u003c/span\u003e\u003cspan address=\"10.1007/BF00377167\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOlivero P, Robillard T (2017) Same-sex sexual behavior in \u003cem\u003eXenogryllus marmoratus\u003c/em\u003e (Haan, 1844) (Grylloidea: Gryllidae: Eneopterinae): Observation in the wild from YouTube. JOR 26:1\u0026ndash;5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3897/jor.26.14569\u003c/span\u003e\u003cspan address=\"10.3897/jor.26.14569\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eO\u0026prime;Neill KM (1994) The Male Mating Strategy of the Ant \u003cem\u003eFormica Subpolita\u003c/em\u003e Mayr (Hymenoptera: Formicidae): Swarming, Mating, and Predation Risk. Psyche 101:93\u0026ndash;108. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/1994/38217\u003c/span\u003e\u003cspan address=\"10.1155/1994/38217\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003e\u0026Oacute;rf\u0026atilde;o I, Calvalho C, Rodrigues I, Ascens\u0026atilde;o L, Pedaccini M, Vicente L, Barbosa M, Varela SM (2023) The role of intrasexual competition on the evolution of male-male courtship display: a systematic review. PeerJ 10:e14638. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.7717/peerj.14638\u003c/span\u003e\u003cspan address=\"10.7717/peerj.14638\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePalaniswamy P, Seabrook WD, Ross RJ (1979) Precopulatory Behavior of Males and Perception of a Potential Male Pheromone in Spruce Budworm, \u003cem\u003eChoristoneura fiimiferana\u003c/em\u003e. Ann Entomol Soc Am 72(4):544\u0026ndash;551\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePan Y, Li W, Deng Z et al (2022) \u003cem\u003eMyc\u003c/em\u003e suppresses male\u0026ndash;male courtship in \u003cem\u003eDrosophila\u003c/em\u003e. EMBO J 41:e109905. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.15252/embj.2021109905\u003c/span\u003e\u003cspan address=\"10.15252/embj.2021109905\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePardi L (1987) Pseudocopulation'of females of \u003cem\u003eOtiorrhynchus pupillatus cyclophtalmus\u003c/em\u003e (Sol.)(Col. Curculion.). Bolletino dell'Istituto di Entomologia della Universit\u0026agrave;. degli Studi di Bologna 41:355\u0026ndash;363\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eParker GA (1970) The Reproductive Behaviour and the Nature of Sexual Selection in \u003cem\u003eScatophaga Stercorarial\u003c/em\u003e (Diptera: Scatophagidae). Behaviour 37(1\u0026ndash;2):140\u0026ndash;168\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeschke K (1987) Cuticular hydrocarbons regulate mate recognition, male aggression, and female choice of the rove beetle. Aleochara curuda J Chem Ecol 13(10):1993\u0026ndash;2008. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF01041727\u003c/span\u003e\u003cspan address=\"10.1007/BF01041727\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePinto JD, Selander RB (1970) The bionomics of blister beetles of the genus Meloe and a classification of the New World species. Ill Biol Monogr 42\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePiper GL (1976) Bionomics of Euarestoides acutangulus (Diptera: Tephritidae)1. Ann Entomol Soc Am 69:381\u0026ndash;386. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/aesa/69.2.381\u003c/span\u003e\u003cspan address=\"10.1093/aesa/69.2.381\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eProkopy RJ, Hendrichs J (1979) Mating Behavior of Ceratitis capitata1 on a Field-Caged Host Tree. Ann Entomol Soc Am 72:642\u0026ndash;648. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/aesa/72.5.642\u003c/span\u003e\u003cspan address=\"10.1093/aesa/72.5.642\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQvick U (1984) A case of abnormal mating behaviour of \u003cem\u003eDolichopus popularis\u003c/em\u003e Wied (Diptera, Dolichopodidae). Not Entomol 64(2):93\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRamm SA, Schlatter A, Poirier M, Sch\u0026auml;rer L (2015) Hypodermic self-insemination as a reproductive assurance strategy. Proc R Soc B 282:20150660. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2015.0660\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2015.0660\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRichardson J, Hoversten IP, Zuk M (2024) Male crickets in poor condition engage in less same-sex sexual behavior. Proc Natl Acad Sci USA 121:e2408811121. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1073/pnas.2408811121\u003c/span\u003e\u003cspan address=\"10.1073/pnas.2408811121\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRichardson J, Zuk M (2023) Rethinking same-sex sexual behaviour: male field crickets have broad mating filters. Proc R Soc B 290:20230002. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rspb.2023.0002\u003c/span\u003e\u003cspan address=\"10.1098/rspb.2023.0002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoberts TM, Thorson RE (1977) Chemical Attraction between Adults of \u003cem\u003eNippostrongylus brasiliensis\u003c/em\u003e: Description of the Phenomenon and Effects of Host Immunity. J Parasitol 63:357. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2307/3280078\u003c/span\u003e\u003cspan address=\"10.2307/3280078\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRocha CFD (1991) Composi\u0026ccedil;\u0026atilde;o do habitat e uso do espa\u0026ccedil;o por \u003cem\u003eLiolaemus lutzae\u003c/em\u003e (Sauria:Iguanidae) em uma \u0026aacute;rea de restinga. Rev Bras Biol 51(4):839\u0026ndash;845\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoth LM (1952) The tergal gland of the male cockroach, \u003cem\u003eSupella supellectilium\u003c/em\u003e. J Morphol 91(3):469\u0026ndash;477\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoth LM, Willis ER (1952) A study of cockroach behavior. Am Midl Nat 47(1):66\u0026ndash;129\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoth LM, Barth RH (1967) The Sense Organs Employed by Cockroaches in Mating Behavior. Behaviour 28:58\u0026ndash;94\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRyne C (2009) Homosexual interactions in bed bugs: alarm pheromones as male recognition signals. Anim Behav 78:1471\u0026ndash;1475. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2009.09.033\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2009.09.033\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSales K, Trent T, Gardner J et al (2018) Experimental evolution with an insect model reveals that male homosexual behaviour occurs due to inaccurate mate choice. Anim Behav 139:51\u0026ndash;59. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anbehav.2018.03.004\u003c/span\u003e\u003cspan address=\"10.1016/j.anbehav.2018.03.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSanders CJ (1975) Factors affecting adult emergence and mating behavior of the eastern spruce budworm, \u003cem\u003eChoristoneura fumiferana\u003c/em\u003e (Lepidoptera: Tortricidae). Can Entomol 107:967\u0026ndash;977. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4039/Ent107967-9\u003c/span\u003e\u003cspan address=\"10.4039/Ent107967-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eScharf I, Martin OY (2013) Same-sex sexual behavior in insects and arachnids: prevalence, causes, and consequences. Behav Ecol Sociobiol 67(11):1719\u0026ndash;1730. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00265-013-1610-x\u003c/span\u003e\u003cspan address=\"10.1007/s00265-013-1610-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchlein Y, Galun R, Ben-Eliahu MN (1981) Receptors of sex pheromones and abstinons in \u003cem\u003eMusca domestica\u003c/em\u003e and \u003cem\u003eGlossina morsitans\u003c/em\u003e. J Chem Ecol 7:291\u0026ndash;303. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF00995752\u003c/span\u003e\u003cspan address=\"10.1007/BF00995752\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eScholes RJ, Monteiro PMS, Sabine CL, Canadell JG (2009) Systematic long-term observations of the global carbon cycle. Trends Ecol Evol 24:427\u0026ndash;430. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.tree.2009.03.006\u003c/span\u003e\u003cspan address=\"10.1016/j.tree.2009.03.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeidelmann K (2023) Age-related changes in cuticular hydrocarbon bouquet and same-sex sexual behavior of mason bee males (\u003cem\u003eOsmia cornuta\u003c/em\u003e and \u003cem\u003eO. bicornis\u003c/em\u003e). Apidologie 54:54. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s13592-023-01029-5\u003c/span\u003e\u003cspan address=\"10.1007/s13592-023-01029-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSerrano JM, Castro L, Toro MA, L࿽pez-Fanjul C (1991) The genetic properties of homosexual copulation behavior in \u003cem\u003eTribolium castaneum\u003c/em\u003e: Diallel analysis. Behav Genet 21:547\u0026ndash;558. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF01066681\u003c/span\u003e\u003cspan address=\"10.1007/BF01066681\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShah DM, Horsch RB, Klee HJ et al (1986) Engineering herbicide tolerance in transgenic plants. Science 233(4762):478\u0026ndash;481. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1126/science.233.4762.478\u003c/span\u003e\u003cspan address=\"10.1126/science.233.4762.478\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShapiro AM (1990) The life histories and behavior of the Patagonian-Fuegian white butterflies \u003cem\u003eHypsochila microdice\u003c/em\u003e and \u003cem\u003eH. galactodice\u003c/em\u003e (Lepidoptera: Pieridae). J NY Entomol Soc 98: 461\u0026ndash;473\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSimon D, Barth RH (2010) Sexual Behavior in the Cockroach Genera \u003cem\u003ePeriplaneta\u003c/em\u003e and \u003cem\u003eBlatta\u003c/em\u003e: II. Sex Pheromones and Behavioral Responses1. Z Tierpsychol 44:162\u0026ndash;177. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1439-0310.1977.tb00991.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1439-0310.1977.tb00991.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSolensky MJ (2004) The Effect of Behavior and Ecology on Male Mating Success in Overwintering Monarch Butterflies (\u003cem\u003eDanaus plexippus\u003c/em\u003e). J Insect Behav 17:723\u0026ndash;743. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1023/B:JOIR.0000048985.58159.0d\u003c/span\u003e\u003cspan address=\"10.1023/B:JOIR.0000048985.58159.0d\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSongvorawit N, Butcher BA, Chaisuekul C (2019) Size Does Not Matter: Same-Sex Sexual Behavior Occurred Regardless of Mandible Size in Male Stag Beetle \u003cem\u003eAegus chelifer chelifer\u003c/em\u003e (Coleoptera: Lucanidae). J Insect Behav 32:282\u0026ndash;289. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10905-019-09733-w\u003c/span\u003e\u003cspan address=\"10.1007/s10905-019-09733-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStojković B, Jovanović DŠ, Tucić B, Tucić N (2010) Homosexual behaviour and its longevity cost in females and males of the seed beetle \u003cem\u003eAcanthoscelides obtectus\u003c/em\u003e. Physiol Entomol 35:308\u0026ndash;316. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1365-3032.2010.00742.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1365-3032.2010.00742.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSpence JR, Wilcox RS (1986) The mating system of two hybridizing species of water striders (Gerridae) II. Alternative tactics of males and females. Behav Ecol Sociobiol 19(2):87\u0026ndash;95\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSturm H (1992) Mating behaviour and sexual dimorphism in \u003cem\u003ePromesomachilis hispanica\u003c/em\u003e Silvestri, 1923 (Machilidae, Archaeognatha, Insecta). Zoologischer Anzeiger 228(1\u0026ndash;2):60\u0026ndash;73\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSwitzer PV, Forsythe PS, Kruse KC (2014) Male-male mounting and the unreliability of body size as a character for mate choice in male Japanese beetles (\u003cem\u003ePopillia japonica\u003c/em\u003e Newman). Zool Stud 53:53. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s40555-014-0053-z\u003c/span\u003e\u003cspan address=\"10.1186/s40555-014-0053-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSyrj\u0026auml;m\u0026auml;ki J (1964) Swarming and mating behaviour of \u003cem\u003eAllochironomus crassiforceps\u003c/em\u003e Kieff.(Dipt., Chironomidae). In Annales Zoologici Fennici. Finnish Zoological Bot Publishing Board 1(2):125\u0026ndash;145\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTakeda K, Furuta T, Hamada M et al (2020) Handicap theory is applied to females but not males in relation to mate choice in the stalk-eyed fly \u003cem\u003eSphyracephala detrahens\u003c/em\u003e. Sci Rep 10:19684. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-020-76649-3\u003c/span\u003e\u003cspan address=\"10.1038/s41598-020-76649-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTauber MJ (1968) Biology, behavior, and emergence rhythm of two species of \u003cem\u003eFannia\u003c/em\u003e (Diptera: Muscidae). Univ Calif Pubis Ent 50:3\u0026ndash;86\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTauber MJ, Toschi CA (1965) Bionomics of \u003cem\u003eEuleia fratria\u003c/em\u003e (loew) (diptera: tephritidae): I. Life history and mating behavior. Can J Zool 43:369\u0026ndash;379. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1139/z65-036\u003c/span\u003e\u003cspan address=\"10.1139/z65-036\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTennent WJ (1987) A note on the apparent lowering of moral standards in the Lepidoptera. Entomol Rec J Var 99:81\u0026ndash;83\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVaias LJ, Napolitano LM, Tompkins L (1993) Identification of stimuli that mediate experience-dependent modification of homosexual courtship in \u003cem\u003eDrosophila melanogaster\u003c/em\u003e. Behav Genet 23:91\u0026ndash;97. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF01067558\u003c/span\u003e\u003cspan address=\"10.1007/BF01067558\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUtzeri C, Belfiore C (1990) Tandem anomali fra Odonati. Fragm Entomol 22:271\u0026ndash;287\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVaias LJ, Napolitano LM, Tompkins L (1993) Identification of stimuli that mediate experience-dependent modification of homosexual courtship in \u003cem\u003eDrosophila melanogaster\u003c/em\u003e. Behav Gen 23(1):91\u0026ndash;97. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF01067558\u003c/span\u003e\u003cspan address=\"10.1007/BF01067558\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Gossum H, De Bruyn L, Stoks R (2005) Reversible switches between male\u0026ndash;male and male\u0026ndash;female mating behaviour by male damselflies. Biol Lett 1:268\u0026ndash;270. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1098/rsbl.2005.0315\u003c/span\u003e\u003cspan address=\"10.1098/rsbl.2005.0315\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWendelken P, Barth RH (1971) The mating behavior of \u003cem\u003eParcoblatta fulvescens\u003c/em\u003e (Saussure and Zehntner) (Blattaria, Blattellidae). Psyche 78(4):319\u0026ndash;329. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/1971/41948\u003c/span\u003e\u003cspan address=\"10.1155/1971/41948\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWendelken PW, Barth RH (1985) On the significance of pseudofemale behavior in neotropical cockroaches. Psyche 92(4):493\u0026ndash;503. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1155/1985/97012\u003c/span\u003e\u003cspan address=\"10.1155/1985/97012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWillis ER (1970) Mating Behavior of Three Cockroaches (\u003cem\u003eLatiblattella\u003c/em\u003e) from Honduras. Biotropica 2:120. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2307/2989769\u003c/span\u003e\u003cspan address=\"10.2307/2989769\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu J, Wang J, Wang Y, Hassan A (2023) Same-sex Pairs Retain Their Reproductive Capacity as a Potential Opportunity for Individual Reproductive Success in Termites. J Insect Sci 23:9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/jisesa/ieac073\u003c/span\u003e\u003cspan address=\"10.1093/jisesa/ieac073\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYamamoto D, Nakano Y (1999) Sexual behavior mutants revisited: molecular and cellular basis of \u003cem\u003eDrosophila\u003c/em\u003e mating. CMLS 56:634\u0026ndash;646. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s000180050458\u003c/span\u003e\u003cspan address=\"10.1007/s000180050458\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYoung CM, Tyler PA, Cameron JL, Rumrill SG (1992) Seasonal breeding aggregations in low-density populations of the bathyal echinoid \u003cem\u003eStylocidaris lineata\u003c/em\u003e. Mar Biol 113:603\u0026ndash;612. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/BF00349704\u003c/span\u003e\u003cspan address=\"10.1007/BF00349704\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"behavioral-ecology-and-sociobiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"beas","sideBox":"Learn more about [Behavioral Ecology and Sociobiology](http://link.springer.com/journal/265)","snPcode":"265","submissionUrl":"https://www.editorialmanager.com/beas/default.aspx","title":"Behavioral Ecology and Sociobiology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"invertebrates, behavioral ecology, homosexual behavior, same-sex sexual behavior","lastPublishedDoi":"10.21203/rs.3.rs-7567028/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7567028/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSame-sex sexual behavior (SSB) in invertebrates encompasses a wide range of interactions, including courtship, mounting, copulation, and pair bonding between individuals of the same sex. Through a systematic review of 219 primary studies and 12 reviews, we found evidence of SSB in 203 species, spanning arthropods, mollusks, annelids, echinoderms, nematodes, and flatworms. Reports were heavily biased toward insects, which represented nearly 90% of the dataset, reflecting research effort rather than true prevalence. Approximately three quarters of the cases were observed in natural conditions, while the remainder derived from laboratory studies. Male\u0026ndash;male copulation and courtship accounted for the majority of reports, but female\u0026ndash;female interactions and reciprocal behaviors were also recorded, the last particularly in hermaphroditic taxa. The main explanatory frameworks identified were mistaken identity or indiscriminate mating, social and environmental influences, and adaptive functions. While non-adaptive mechanisms remain a plausible explanation in some contexts, adaptive roles were supported by multiple cases, including enhanced mating practice, reproductive assurance, anti-predator strategies, and stress relief. Fitness consequences were rarely measured directly, but when reported they revealed both costs, such as reduced lifespan or genital injury, and benefits, such as improved reproductive success under biased sex ratios. The synthesis of available evidence suggests that SSB is not an anomaly but a flexible component of reproductive strategies in invertebrates. Rather than being maladaptive, it emerges as context-dependent behavior influenced by ecological and social pressures, and in some cases may confer selective advantages.\u003c/p\u003e","manuscriptTitle":"Same-Sex Sexual Behavior in invertebrates is widespread and context-dependent: insights from a Systematic Synthesis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-12 13:59:15","doi":"10.21203/rs.3.rs-7567028/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-17T17:54:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-12T10:22:29+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-12T00:56:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Behavioral Ecology and Sociobiology","date":"2025-09-08T18:47:10+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"behavioral-ecology-and-sociobiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"beas","sideBox":"Learn more about [Behavioral Ecology and Sociobiology](http://link.springer.com/journal/265)","snPcode":"265","submissionUrl":"https://www.editorialmanager.com/beas/default.aspx","title":"Behavioral Ecology and Sociobiology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"d103cc12-dc3e-48fa-be46-fc17aabc0328","owner":[],"postedDate":"October 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T19:21:49+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-12 13:59:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7567028","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7567028","identity":"rs-7567028","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}