Population trends of three endangered butterflies under the influence of forest restoration and human disturbance in Qinling Mountains

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Threat factors were provided. The results showed that the number of host plants and larvae of the three specialist butterflies, namely the Luehdorfia taibai , Luehdorfia chinensis huashanensis , Bhutanitis thaidina decreased to varying degrees. Among them, the density of the host plant of Luehdorfia taibai decreased from 2.23 plants/㎡ in 2011 to 0.13 plants/㎡ in 2023, and no eggs and larvae were found in 2023-2025. The density of the host plant of the Luehdorfia chinensis huashanensis decreased by 71.33%, and the average insect plant rate decreased by 37.03%. The density of host plants of Bhutanitis thaidina decreased by 65.52%, and the rate of insect plants decreased by 43.29%. The main reason for the decline is that the forest is too dense, which leads to the disappearance of glades, the dense forest restricts the oviposition of adults, and the lack of heat under the forest affects the development of larvae. Artificial excavation leads to insufficient number of host plants, and the larvae on the leaves are sunburned. In addition, there is interspecific competition, predation by natural predators, climate change, etc. Population conservation and restoration strategies include habitat management, protection of host plants, in-situ artificial culture, and public education. Forest restoration Endangered butterflies Population trends Threat factors Protective measures Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Forests constitute the most critical ecosystem on Earth, providing multidimensional ecosystem services. These include provisioning services such as timber, fiber, food, and medicinal herbs; regulating services encompassing soil conservation, water retention, pollution purification, carbon sequestration and oxygen release; and cultural services like forest aesthetics and ecotourism. Crucially, forests sustain rich biodiversity by offering habitats for wildlife. Research indicates that approximately 80% of terrestrial biodiversity relies on forest ecosystems for survival (Kingdom, 2005). The accelerated global industrialization has exacerbated over exploitation and irrational utilization of natural resources, leading to habitat fragmentation and loss. These processes manifest as reduced habitat area, intensified edge effects, and isolated habitat patches (Pullin, 2005; Fang & Guan, 2010). Such changes profoundly impact forest-dwelling species, with habitat loss and fragmentation recognized as primary drivers of species extinction. Current extinction rates are estimated to be 100,000 times higher than natural background rates, with approximately 75 species disappearing daily (Wilson, 1993). The IPBES (2019) report reveals that one million species worldwide face extinction threats, with endangered proportions reaching 48% for mammals, 49% for birds, and 64% for amphibians (Wu & Li, 2003). As key components of ecological chains, butterfly population declines may trigger ecosystem cascades (Paine &Robert,1966). Consequently, forest conservation, habitat restoration, and biodiversity maintenance have become urgent global priorities. Over 20,000 butterfly species are documented globally, with China recording more than 1,700 species (Chou, 1999; Wu & Xu, 2017). Butterflies play key roles in ecosystems as pollinators for wild plants, participants in nutrient cycling and energy flow, and organisms with life cycles tightly linked to plant communities (Ollerton et al., 2011; William et al., 1975; Yang & Gratton, 2014). Compared to other insects, butterflies exhibit moderate body size, diurnal activity patterns, and high sensitivity to environmental changes, making them vital bioindicators of ecological health (Thomas, 2005; Liu et al., 2018; Yin et al., 2023). Studies demonstrate their response rates to environmental disturbances such as habitat degradation and climate change exceed those of host plants by 3–30 times (Hu et al., 2010; Maes & Dyck, 2001), establishing them as ideal subjects for biodiversity monitoring and ecological restoration evaluation (Kumar et al., 2009). Habitat restoration impacts butterfly diversity in complex ways. Moderate anthropogenic disturbances like secondary forest management may enhance diversity, while intensive disturbances such as monoculture plantations lead to species homogenization (Vu, 2009; Vu & Vu, 2011). For example, European semi-natural grasslands lost 80% of their area due to excessive mowing, causing drastic butterfly diversity declines, though scientific grazing and reduced mechanical intervention stabilized certain populations (Humbert et al., 2010; Jan et al., 2016; Joanna et al., 2016; Joanna & Piotr, 2023; Joyce & Chris, 2014). Forest restoration similarly demonstrates dual effects: The Karner blue butterfly Lycaeides melissa samuelis became endangered when canopy density exceeded 60%, reducing host plant availability (Grundel et al., 1998), while China’s Luehdorfia taibai experienced population collapse due to excessive canopy closure in secondary forests (Guo et al., 2014). These cases highlight habitat heterogeneity management as critical for balancing restoration and conservation (Botham et al., 2015; Michael & Kessler, 2000; Rowe et al., 2015). Global studies indicate butterfly diversity is influenced by interactions among vegetation structure, climatic conditions, and anthropogenic interventions. In temperate forests, canopy gaps with 30%–60% openness optimize butterfly oviposition and host plant growth (Grundel et al., 1998). Tropical rainforest restoration requires maintaining understory light gradients to support niche-differentiated species (Humbert et al., 2010). Domestic research focuses on endangered species mechanisms, conservation strategies, geographic distribution patterns (Wang et al. 2024), and habitat change impacts. For instance, studies include conservation research on the Luehdorfia Taibai in Qinling Mountains (Guo et al., 2014), population ecology of the Byasa impediens (Li et al., 2012), and habitat selection of the Teinopalpus aureus (Yang et al., 2024). Vegetation community stability directly affects butterfly population dynamics, with generalist taxa like Pieridae and Nymphalidae dominating fragmented habitats while habitat specialists decline (Han et al., 2022). The Qinling Mountains, a biodiversity hotspot in China, harbor over 900 butterfly species (Fang, 2019). Three habitat specialists include the Bhutanitis thaidina and the Luehdorfia chinensis huashanensis , both listed as National Grade II Protected Species (He, 1989), and the critically endangered Luehdorfia taibai . These three species of butterflies belong to habitat-specific species, which have strict requirements for habitat microenvironment and are easily affected by human disturbance and habitat changes.Research conducted in 2011–2012 within Taibai Mountain Nature Reserve identified threats including host plant over harvesting, excessive canopy closure, and climate change (Gao et al., 2013; Guo et al., 2014). Eleven years later, intensified canopy closure and persistent plant harvesting likely altered their survival status. Follow-up surveys from 2023 to 2025 assessed population trends, analyzed threats, evaluated endangerment levels, and proposed conservation strategies. This work aims to enhance governmental and public awareness, promote participatory conservation, and implement science-based measures to ensure these species’ long-term survival. 1. Research methods 1.1 Research species （ 1 ） Luehdorfia taibai Luehdorfia taibai , an endemic Chinese species, inhabits shaded, moist areas along mountain streams at elevations of 1000–1800 m in the Taibai Mountain Nature Reserve, Zhouzhi Nature Reserve, and Xiaolongshan Baihualin Forest Farm of the Qinling Mountains. This univoltine species overwinters as pupae, with adults emerging in mid-to-late April. Adults prefer habitats with stronger illumination, typically inhabiting forest edges or canopy gaps. After emergence and mating, females oviposit on the abaxial surfaces of leaves of the host plant Saruma henryi , selecting sites with thick litter layers. Larvae feed exclusively on S. henryi , completing larval development in approximately 40 days before pupating in mid-June, with pupal diapause lasting 280 days (Guo et al., 2014). Figure 1-A,D. （ 2 ） Luehdorfia chinensis huashanensis Luehdorfia chinensis huashanensis , a Qinling Mountains endemic subspecies in China, is categorized as a National Grade II Protected Species under the National Key Protected Wildlife List. This subspecies is distinguished from Luehdorfia chinensis primarily by its geographic distribution and host plant specificity. Luehdorfia chinensis huashanensis occurs in the central Qinling's Taibai Mountain Nature Reserve and eastern Huashan region, utilizing Aristolochia sieboldii as its exclusive host plant (Figure 1-B, E). In contrast, the nominate subspecies Luehdorfia chinensis inhabits the middle-lower Yangtze River basin (Hunan, Jiangsu, and Jiangxi provinces), with Asarum forbesii serving as its host plant (Yuan et al., 1998; Zou, 2024). （ 3 ） Bhutanitis thaidina Bhutanitis thaidina inhabits subalpine shrublands and forest edges at elevations of 1092 and 3448 m across the Qinling, Minshan, Hengduan and Shennongjia Mountains, favoring habitats with canopy densities of 0.4–0.75 (Gao et al.,2013; Lv et al.,2025). This univoltine species overwinters as pupae, with adults active from late May to early July. Adults exhibit strong flight capabilities, engaging in courtship, mating, and nectar-feeding in sunlit areas. Larvae develop for approximately 40 days, feeding exclusively on Aristolochia manshuriensis in Taibai Mountain, where females deposit eggs on the abaxial surfaces of host plant leaves (Gao et al.,2013). Figure 1-C, F. 1.2 R esearch site This study was conducted in forests surrounding Houzhenzi Town on the southern slope of Taibai Mountain in the Qinling Mountains. As the highest peak of the Qinling range (3,767 m elevation), Taibai Mountain spans Taibai, Mei, and Zhouzhi counties, with geographic coordinates spanning 33°49'–34°10'N and 107°19'–107°58'E (Qin et al., 2016). Characterized by cool temperatures and abundant rainfall year-round, the mountain exhibits vertical vegetation zonation comprising deciduous broadleaf forests, coniferous forests, alpine shrublands, and meadow belts from base to summit (Ren et al., 2011). Elevation-dependent climatic zones include temperate monsoon (800–1,500m), cold-temperate monsoon (1,500–3,000m), subarctic (3,000–3,360m), and arctic climates (above 3,360m) (Tang, 2017). Qinling's forests underwent extensive logging from the 1980s to 1990s, leading to reduced canopy coverage, structural simplification, functional degradation, and diminished ecosystem services, negatively impacting wildlife including giant pandas. Since China's 1998 logging ban and implementation of the Natural Forest Protection Program, forest recovery over two decades has increased canopy coverage and wildlife populations. GIS-based measurements indicate landscape-scale forest coverage increased from 86.11% in 2000 to 90.5% in 2023. Figure 2. 1.3 Field survey method （ 1 ） Biological characteristic bservation of Luehdorfia chinensis huashanensis Field observations and semi-wild rearing were combined for study. A 40×50 m experimental plot was established using Asarum sieboldii cultivated by local farmers under forest canopies. After A. sieboldii sprouted in mid-April, gravid females of L. chinensis huashanensis were attracted to oviposit. Eggs were tagged on petioles post-oviposition, with records of oviposition dates, egg counts, and daily monitoring to determine hatching dates and egg development duration. Post-hatching, larval feeding, molting, and developmental stages were tracked, including instar durations and prepupal behaviors. Adult flower-visiting and mating behaviors were documented in forest-edge valleys. （ 2 ） Life Table Analysis of Luehdorfia chinensis huashanensis Life table construction identified critical endangerment factors. Egg clusters on host plants were tagged across habitat patches. Regular monitoring recorded population changes in eggs and larvae, mortality rates, causes of death, and prepupal behaviors until pupation. Habitat parameters were systematically logged. Sublethal mortality (*k*) for each factor was calculated as: k = lgN – lgNs where N = initial population size, N_s = surviving individuals post-factor exposure. （ 3 ） Sample survey for Host Plant Density, Egg, and Larval Counts The host plants for Luehdorfia taibai ( Saruma henryi ) and Luehdorfia chinensis huashanensis ( Asarum sieboldii ) are predominantly distributed under forest canopies, with eggs and larvae located on the abaxial leaf surfaces. To survey eggs and larvae, 5×5 m sample were randomly established in areas with potential host plant presence. Within each sample, host plant counts and egg/larval numbers per plant were recorded. 22 sample across 5 sites from April to June in 2012 were conducted. 26 sample across 3 sites from April to June in 2023–2024 were conducted . For Bhutanitis thaidina (host plant: Aristolochia manshuriensis ), surveys focused on cliff faces and rocky gaps: 31 sample(5×5 m ) across 4 sites from May to July were conducted in 2023–2024 and compared with 27 sample across 8 sites in 2012 were conducted. （4） Adult Population Surveys Transects (5×500–2000 m) were established in high-elevation valleys, streams, forest edges, or canopy gaps (canopy density <0.6). Transect parameters (altitude, coordinates, vegetation cover) and observed adults, nectar plants, and anthropogenic disturbances were recorded. L.taibai and L. chinensis huashanensis : 4 times surveys (April–May 2012; April–May 2023–2025). B. thaidina : 2 surveys May–July 2023–2024). （5） Data Analysis Key metrics: Host plant density : Total plants / sample area (m²). Infested plant rate : (Infested plants / total plants) × 100%. Larval density per plant : Total larvae / total plants. For Luehdorfia chinensis huashanensis , anthropogenic threats (host plant harvesting for traditional medicine) were analyzed using infested plant rate as the response variable. Predictors included altitude ( X₁ ), host plant density ( X₂ ), and forest cover ( X₃ ). Principal Component Analysis (PCA) addressed multicollinearity, followed by regression modeling to quantify variable relationships. 2. Research results 2.1. Population Trends of Luehdorfia taibai During 2011–2012, 22 sample with 5×5 m were surveyed in understory and forest-edge habitats near Houzhenzi Town on Taibai Mountain’s southern slope, within the elevational range of 1,073–1,589 m. These sample exhibited an average forest cover of 67.27%, with host plant Saruma henryi density averaging 2.22 plants/m². Egg clusters were detected on 55% of host plants, averaging 17.16 eggs per clutch (Guo et al., 2014). In 2023–2024, surveys 26 sample with 5×5 m (elevation: 1,004–1,498 m) revealed a 73.08% average forest cover canopy but a drastic 94.2% decline in host plant density to 0.13 plants/m² (Appendix 1). No eggs or larvae were recorded. Follow-up 2025 surveys of 4 sample showed marginally higher host plant density (0.48 plants/m², Appendix 1-2), yet still no eggs or larvae were observed.This trajectory demonstrates that increasing forest cover (resulting in canopy closure and loss of sunlit gaps) has directly reduced suitable habitats for Luehdorfia taibai , triggering host plant depletion and subsequent population collapse. The complete absence of reproductive indicators (eggs/larvae) in recent surveys suggests local extirpation risks under current forest succession patterns. 2.2 Life History and Threat Factors of Luehdorfia chinensis huashanensis 2.2.1 Behavioral Ecology of Luehdorfia chinensis huashanensis Luehdorfia chinensis huashanensis is distributed in the Taibai Mountain region at elevations above 1,600 m, with population concentrations between 1,800–2,000 m. This subspecies exhibits a univoltine life cycle, overwintering as pupae and emerging as adults in mid-to-late April. Adults demonstrate strong flight capabilities, traveling considerable distances to locate nectar sources and host plants, primarily foraging on Cerasus species (Rosaceae), and favoring sunlit, moderately dry microhabitats at forest edges. Males employ a patrolling mating strategy, pursuing females until mating acceptance. Post-copulation, females develop a brown chitinous shield (~5 mm diameter) at the genital opening to prevent subsequent mating attempts. Eggs are deposited in clusters on the abaxial surfaces of the host plant Aristolochia sieboldii (Figure 3-A), typically containing 6–14 eggs per cluster (rarely singly), spaced ~1 mm apart, with ≤2 clusters per leaf. Eggs are subglobose (1.0 mm diameter), initially pale green with pearlescent luster, transitioning to translucent white prior to hatching, with larval head capsules visible through the chorion. Egg development spans 12–14 days, extendable under prolonged rainfall Larvae undergo five instars: newly hatched larvae exhibit black heads, brown bodies, and fine setae, remaining gregarious until the third instar, often aligning linearly when resting (Figure 3-B). Post-third instar, larvae disperse and exhibit nocturnal feeding patterns, hiding beneath host plant roots or leaf litter during daylight and rapidly everting osmeteria when disturbed. The larval stage lasts ~40 days, with extended duration during the fifth instar. Mature larvae (Figure 3-C) pupate within leaf litter or rock crevices, securing themselves via silk threads during a 2–3 day prepupal stage. Pupae are suspensory, dark brown, rigid, and texturally rugose (Figure 3-D), undergoing diapause for ~280 days. 2.2.2 Life table of the Luehdorfia chinensis huashanensis Larval mortality is primarily influenced by anthropogenic harvesting of its host plant Asarum sieboldii , secondarily associated with rain scouring, natural enemies (predominantly spiders and ants), and diseases. Population life table data are presented in Table 1. Table 1 Life Table of Larvae Population of Luehdorfia chinensis huashanensis in Taibai Mountain （April to Jun 2012） Develop stage x Population count lx Cause of mortality dxF Mortality count dx Mortality rate 100qx Survival rate 100sx K Eggs 106 39 36.79 63.21 Unhatched 8 7.55 92.45 k1= 0.1992 Mortality due to anthropogenic harvesting of host plants 31 29.25 70.75 k2= 0.03408 1st–3rd instar larvae 67 55 82.09 17.91 Rainfall 15 22.39 77.61 K3=0.1101 Mortality due to bacterial infection 3 4.48 95.52 K4=0.01990 Predation by natural enemies 16 23.88 76.12 K5=0.1185 Mortality due to anthropogenic harvesting of host plants 21 31.34 68.66 K6=0.1633 4th–5th instar larvae 12 Predation by natural enemies 1 8.33 91.67 K7=0.03779 Pupa 11 Table 1 demonstrates that anthropogenic harvesting of host plants exerted the highest impact during the 1st–3rd instar larval stage (k₆ = 0.1633), followed by predation from natural enemies (k = 0.1185). 2.2.3 Impact of Anthropogenic Harvesting of Host Plants ( Asarum sieboldii ) on Population Viability of Luehdorfia chinensis huashanensis （1） Oviposition Site Selection Analysis of oviposition site selection revealed significant correlations between elevation ( X₁ ) and host plant density ( X₂ ) (Figure 4). Principal Component Analysis (PCA) of 2012 survey data extracted two principal components (cumulative contribution rate: 83.9%). The derived regression equation after coefficient transformation was:y= 3.041513431+0.002297815 -0.016266396-0.061687671。This indicates that within suitable habitats, oviposition frequency of Luehdorfia chinensis huashanensis increases with higher elevation ( X₁ ), elevated host plant density ( X₂ ), and reduced forest cover ( X₃ ) ( F = 7.998, *p* = 0.006). Semi-wild rearing environments with artificially enhanced host plant density also elicited oviposition behavior. Notably, infested plant rates dropped to 0% in areas experiencing host plant harvesting. Destructive harvesting practices have caused localized extirpation of Asarum sieboldii populations in habitats such as Qingshuihe valey. （2） Population Trends and Endangerment Mechanisms of Luehdorfia chinensis huashanensis The host plant Asarum sieboldii (Figure 5-B), a medicinal herb subjected to intensive harvesting due to high market demand (Figure 5-A), thrives in forest understories. Based on the presence/absence of eggs or larvae in 2023–2024 surveys, sample were classified as "occupied" (host plants with eggs/larvae) or "unoccupied" (host plants only). Comparative analyses revealed no significant differences between occupied and unoccupied sample in elevation (*t* = -0.055, *p* > 0.05), canopy density (*t* = 0.803, *p* > 0.05), or host plant density (*t* = 1.689, *p* > 0.05), indicating habitat homogeneity across these parameters. Longitudinal analysis (11-year interval) quantified host plant decline. 20 sampling in 2011-2012 shows averaged 89.5% forest cover canopy, with A. sieboldii density of 2.79 plants/m² and larval density of 3.16 larvae/plant (Appendix 2-1).34 sampling in 2023-2024 showed a 71.33% reduction in host plant density (0.856 plants/m²) and a 95.03% decline in larval density (0.18 larvae/plant) (Appendix 2-2). This precipitous decline correlates directly with anthropogenic harvesting pressure and habitat homogenization, underscoring the subspecies' critical endangerment status. 2.3 Population Trends of Bhutanitis thaidina Gao et al. (2014) reported a host plant density of 0.406 plants/m² and an larvae infested plant rate of 5.29% across 32 sampling surveyed during 2011–2012. In 2023–2024, resurveys of 28 sampling in the same locations revealed a 65.52% decline in host plant density (0.14 plants/m²) and a 43.29% reduction in infested plant rate (0.003 larvae/plant) (Appendix 3). These findings correlate with rising forest coverage, demonstrating significant adverse impacts on Bhutanitis thaidina survival through concurrent declines in host plant availability and larval populations. 3. Discussion 3.1 Survival Status of the Three Butterfly Species Longitudinal surveys spanning 11 years revealed critical declines across all three species: Luehdorfia taibai : No adults, eggs, or larvae were detected during 2023–2025 surveys in historical habitats, indicating potential local extinction. Luehdorfia chinensis huashanensis : Host plant ( Asarum sieboldii ) density declined by 71.33%, accompanied by a 37.03% reduction in larvae infested plant rate, signaling marked population contraction. Bhutanitis thaidina : Host plant ( Aristolochia manshuriensis ) density decreased by 65.52%, with a 43.29% decline in larvae infested plant rate. These trends correlate strongly with anthropogenically driven forest succession, which eliminates critical open-canopy microhabitats and disrupts host plant availability. 3.2 Analysis of Endangerment Factor Population declines and local extinctions of the three butterfly species exhibit significant correlation with host plant depletion ( R² = 0.72, *p* < 0.01), supporting the "co-extinction hypothesis" (Ehrlich & Raven, 1964). This posits that plants and insects form interdependent networks through complex interactions (e.g., defense, mutualism, resource competition), where extinction of one may cascade to the other via ecological linkages. （1） Endangerment Mechanisms of Luehdorfia taibai Implementation of China’s Natural Forest Protection Program restored forest canopy density from 86.11% (2000) to 90.58% (2023), eliminating critical sunlit gaps. Resultant understory light and thermal insufficiency suppressed host plant Saruma henryi growth, reducing density from 2.23 to 0.13 plants/ m² (*p* < 0.01). Dense canopies further impeded adult flight and oviposition behaviors. （ 2 ） Endangerment Mechanisms of Luehdorfia chinensis huashanensis Harvesting of host plants is thought to be the main cause of its decline. With the increase of market demand, the price of the host plant Asarum sieboldii , which is used as a Chinese herbal medicine, has risen from 120 CNY/kg in 2012 to 400 CNY/kg in 2024. Driven by economic interests, mining intensified, and host plant density decreased by 64%. Microhabitat degradation : Increased canopy density reduced understory light availability, impairing A. sieboldii growth and larval development while hindering adult oviposition. （ 3 ） Endangerment Mechanisms of Bhutanitis thaidina Canopy closure : Loss of forest gaps restricted adult movement and oviposition, while understory thermal deficits delayed larval development. Interspecific competition : Intensified resource competition with Byasa polyeuctes , a numerically dominant congener sharing Aristolochia manshuriensis (Guo et al., 2014; Lv et al., 2025). Predation pressure : Larval mortality exceeded 90% due to diverse forest predators (Guo et al., 2014). Climate-driven range shifts : Upward elevational migration of adults outpaced host plant colonization, limiting successful establishment (Lv et al., 2025). 3.3 Conservation Strategies （ 1 ） Habitat Management Implement targeted forest management in native habitats of Luehdorfia taibai , Luehdorfia chinensis huashanensis , and Bhutanitis thaidina . Key interventions include periodic canopy thinning, coppicing, shrub clearance, and replanting host plants to restore understory environments conducive to host plant growth and adult activity. （ 2 ） Host Plant Protection Include host plants of all three species ( Saruma henryi , Asarum sieboldii , and Aristolochia manshuriensis ) in the National Key Protected Plant List to curb illegal harvesting, ensuring simultaneous protection of plants and butterflies. （3） In Situ Captive Breeding and Population Recovery Establish conservation bases near extant habitats, replicating natural conditions (light intensity >2000 lux, canopy density 40%–60%). Cultivate host plants and nectar sources to attract ovipositing adults, enhance larval development, and boost population numbers (Guo et al., 2014). （4） Public Education Campaigns Distribute conservation pamphlets highlighting butterfly ecological importance and risks of Aristolochiaceae plants (containing carcinogenic aristolochic acid). Discourage public use of these plants in traditional medicine and culinary practices. Declarations Acknowledgement We are sincerely grateful to Dr. Ruikun Gou who works for Northwest F&F University take the Arc GIS Analysis on forest cover canopy. Author contributions LZ: conducted field work from 2023-2024 and wrote the main manuscript text. ZG: conducted field work from 2011-2012. XL: designed the research framework and revised the manuscript text. YX: conducted the field work. YZ: revised the manuscript. JS: revised the manuscript. All authors reviewed the manuscript. Funding National Key R and D Program of China, 2022YFE0115200, Scientifc Research initial project of CWNU, 20E064. Data availability No datasets were generated or analyzed during the current study. Conflict of interest The authors declare no competing interests. References Botham MS, Fernandez-Ploquin EC, Brereton T, Harrower CA, Roy DB, & Heard MS (2015) Lepidoptera communities across an agricultural gradient: how important are habitat area and habitat diversity in supporting high diversity? Journal of Insect Conservation , 19(2), 403-420. Chou I (1999) Monograph of Chinese butterflflies. Henan Scientifific and Technological Publishing House, Henan (in Chinese) Ehrlich PR, & Raven PH (1964) Butterflies and Plants: A Study in Coevolution. Evolution , 18(4), 586-608. Fang L, & Guan J (2010) Responses of butterflies to global climate change and research progress. Journal of Environmental Entomology , 32(3), 9..(in Chinese with English abstract) Fang L（2024）The Butterfly Chronicles of the Great Qinling, Xi'an Publishing House Gao K (2013) Study on the endangered mechanisms and conservation of Bhutanitis thaidina (Blanchard) in Taibai Mountain region [Master’s thesis, Northwest A&F University]. CNKI. https://link.cnki.net/doi/10.27409/d.cnki.gxbnu.2013.000108.(in Chinese with English abstract) Grundel R, Pavlovic NB, & Sulzman CL (1998) Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover. Biological Conservation , 85(1), 47-53. Guo Z, Gao K, Li X, & Zhang Y (2014) Biology and habitat research of the Luedorfia Taibai . Acta Ecologica Sinica , *34*(23), 6943–6953..(in Chinese with English abstract) Han D, Wang C, Sun Z, She J, Yin L, Bian Q, & Han W (2022) Microhabitat preferences of butterflies in urban parks: both vegetation structure and resources are decisive. Urban Forestry &Amp; Urban Greening Hu B, Li H, Zhipin L, & Tiejian Z (2010) Diversity and fauna of butterflies in Baxian Mountain State Nature Reserves. Acta Ecologica Sinica , 30(12), 3226-3238. Humbert JY, Ghazoul J, Sauter GJ, & Walter T (2010) Impact of different meadow mowing techniques on field invertebrates. Journal of Applied Entomology (7), 134. IPBES report: Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.Publication | 2019 Jan, Christian, Habel, Mike, Teucher, Werner, Ulrich, Markus, Bauer, & Dennis (2016) Drones for butterfly conservation: larval habitat assessment with an unmanned aerial vehicle. Landscape Ecology , 31(10), 2385-2395. Joanna KB, Piotr S, Piotr N, Maciej B, Aw KW, Damian SY, Michal W, & Banks SC (2016) Relative Contribution of Matrix Structure, Patch Resources and Management to the Local Densities of Two Large Blue Butterfly Species. Plos One , 11(12), e168679. Joanna K, & Piotr N (2023) Vanishing meadows — Quantitative analysis of factors driving population declines of endangered butterflies. Biological Conservation , 282 Joyce, & Chris B (2014) Ecological consequences and restoration potential of abandoned wet grasslands. Ecological Engineering , 66, 91-102. Kingdom U (2005) Global Forest Resources Assessment 2020 Kumar S, Simonson SE, & Stohlgren TJ (2009) Effects of spatial heterogeneity on butterfly species richness in Rocky Mountain National Park, CO, USA. Biodiversity & Conservation , 18(3), 739-763. Li X, Zhang Y, Settele J, Franzen M and Schweiger O (2012) Long-distance dispersal and habitat use of the butterflfly Byasa impediens in a fragmented subtropical forest.Insect Conservation and Diversity (2012) doi: 10.1111/j.1752-4598.2012.00199.x Liu N, Liu Z., Yu L, Zhang Y, Chu J, Yin RC, & Fang J (2018) Species diversity and faunal composition of butterflies in Yaoluoping National Nature Reserve. Genomics and Applied Biology , *37*(5), 6..(in Chinese with English abstract) Lv F, Li X, Zhang L, Chang X, Zuo X (2025)Distribution, Habitat Preferences, and Threat Factors of theButterfly Bhutanitis thaidina. DOI : 10.1007/s10841-025-00677-5 Maes D, & Dyck HV (2001) Butterfly diversity loss in Flanders (north Belgium): Europe's worst case scenario? Biological Conservation , 99(3), 263-276. Michael & Kessler (2000) Elevational gradients in species richness and endemism of selected plant groups in the central Bolivian Andes. Plant Ecology Ollerton J, Winfree R, & Tarrant S (2011) How many flowering plants are pollinated by animals? Oikos , 120(3) Pullin AS (2005) Conservation biology (Chinese ed.). Beijing: Science Press. (in Chinese with English abstract) Paine, & Robert T (1966). Food Web Complexity and Species Diversity. American Naturalist , 100(910), 65-75. Qin J, Bai H, Li S, Wang J, Gan Z, & Huang A (2016) Differential responses of Larix chinensis at the alpine timberline on the northern and southern slopes of Taibai Mountain to climate change. Acta Ecologica Sinica , *36*(17), 5333–5342..(in Chinese with English abstract) Ren X , Yang G, Wang D, Qin X, Liu Z, Zhao S, Bai Y, Ren X, Yang G, & Wang D (2011) Study on the minimum sampling area of shrub and herb layers in several plant communities in Taibai Mountain. Acta Botanica Boreali-Occidentalia Sinica , *31*(5), 8..(in Chinese with English abstract) Tang H (2017) Taibai County Annals: 1990–2010 ..(in Chinese with English abstract) Thomas JA (2005) Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups. Philosophical Transactions of the Royal Society B Biological Sciences , 360(1454), 339-357. Vu LV (2009) Diversity and similarity of butterfly communities in five different habitat types at Tam Dao National Park, Vietnam. Journal of Zoology , 277 Vu LV, & Vu CQ (2011) Diversity Pattern of Butterfly Communities (Lepidoptera, Papilionoidae) in Different Habitat Types in a Tropical Rain Forest of Southern Vietnam. Isrn Zoology , (1) Wang D, Zhang Y, Lu L, Li S & Wang R (2024) Butterfly Diversity Patterns Provide New Insights Into Biodiversity Conservation in China.Global Ecology and Biogeography, 34(1), e13946-e13946. William J, Mattson, Norton D, & Addy (1975) Phytophagous Insects as Regulators of Forest Primary Production. Science , 190(4214), 515-522. Wilson EO (1993) The Diversity of Life . Macmillan. Wu CS, Xu YF (2017) Butterflies of China. Straits Publishing House. Yang L, & Gratton C (2014) Insects as drivers of ecosystem processes - ScienceDirect. Current Opinion in Insect Science , 2, 26-32. Yang W, He G, Huang C, Zhou S, Jia F, Zeng J (2024) Application of noninvasive sampling technique in mitochondrial genome intraspecific phylogeny of the endangered butterfly, Teinopalpus aureus (Lepidoptera: Papilionidae), Insect Science, 24(1):16;1-12. Yin J, Shi W, Wang L, Wang Y, Li C, He Q, & Yi C (2023) Study on the community structure and species diversity of butterflies in Yuanyang County, Yunnan Province. Journal of Yunnan Agricultural University (Natural Science) , *38*(5), 771–778..(in Chinese with English abstract) Yuan D, Mai G, Xue D, Hu C, & Ye G (1998) Habitat, biology, and conservation status of the Chinese tiger swallowtail butterfly ( Luehdorfia chinensis ). Biodiversity Science , *6*(2), 105–115..(in Chinese with English abstract) Zou M (2024) Study on the limiting effects of the host plant Asarum forbesii on the Taohongling population of Luehdorfia chinensis and its growth conditions [Master’s thesis, Jiangxi Agricultural University]..(in Chinese with English abstract) Sandra Díaz, Josef Brondizio Co Settele , Eduardo Chairs GA.Global Assessment Report on Biodiversity and Ecosystem Services – Implications for the Global Biodiversity Framework. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-6780797","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":475382330,"identity":"625502dd-dd03-404d-a980-674193291e61","order_by":0,"name":"Liqiu Zhang","email":"","orcid":"","institution":"China West Normal University","correspondingAuthor":false,"prefix":"","firstName":"Liqiu","middleName":"","lastName":"Zhang","suffix":""},{"id":475382331,"identity":"9085a220-e5a7-4b72-a78d-32ff6cb9e821","order_by":1,"name":"Zhenying Guo","email":"","orcid":"","institution":"Xinxiang Academy of Agricultural Sciences","correspondingAuthor":false,"prefix":"","firstName":"Zhenying","middleName":"","lastName":"Guo","suffix":""},{"id":475382332,"identity":"6dcc81c6-b89d-477f-8b8f-3100f4f28341","order_by":2,"name":"Xiushan Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIie3RsYrCMBjA8U8C6fJV15RK+wopAfFxKgc3yVEQxEGOQEA3576HLxAJ1PHWG27xBKfbCo5iWieXWLcD8ydDhvz4EgLg8/3HSLtgSAMJGoAlaVeCFHVDxiKT3QYBAsub/WLSQGd8j6Iulj/Yj/4yU1jYk+Tw++0gkcJRXFYnpPGUmxLYRwBUiKmDDAiOCFJjyXtu7PVmPdlwB6HEXgwvlkRVSyZSPyB2Co/DlSWM6G4kUnQehxtL8E2bkjORqQdv4V9mW+PZJOl6p+pi8ZmkgTocXeQuAhxu39S5pw77fD7f63QFi6Y9Qsij+AIAAAAASUVORK5CYII=","orcid":"","institution":"China West Normal University","correspondingAuthor":true,"prefix":"","firstName":"Xiushan","middleName":"","lastName":"Li","suffix":""},{"id":475382333,"identity":"e9807083-4234-4059-81f7-2eef666efc8d","order_by":3,"name":"Yan Xia","email":"","orcid":"","institution":"China West Normal University","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Xia","suffix":""},{"id":475382334,"identity":"ed79029b-347f-4c09-ae73-997e932d4044","order_by":4,"name":"Yalin Zhang","email":"","orcid":"","institution":"College of Plant Protection, Northwest A\u0026F University","correspondingAuthor":false,"prefix":"","firstName":"Yalin","middleName":"","lastName":"Zhang","suffix":""},{"id":475382335,"identity":"fb5266de-7843-498d-8ef9-5332670dfa71","order_by":5,"name":"Josef Settele","email":"","orcid":"","institution":"Helmholtz Centre for Environmental Research","correspondingAuthor":false,"prefix":"","firstName":"Josef","middleName":"","lastName":"Settele","suffix":""}],"badges":[],"createdAt":"2025-05-30 04:08:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6780797/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6780797/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85394564,"identity":"d208b164-51a0-4afc-a17f-d7f28695822c","added_by":"auto","created_at":"2025-06-25 10:57:22","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1234473,"visible":true,"origin":"","legend":"\u003cp\u003eAdults of three rare butterflies and their host plants\u003c/p\u003e\n\u003cp\u003eA. \u003cem\u003eLuehdorfia taibai， B. Luehdorfia chinensis huashanensis，\u003c/em\u003eC. \u003cem\u003eBhutanitis thaidina，\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eD.\u003cem\u003eSaruma henryi,h\u003c/em\u003eost plants of \u003cem\u003eLuehdorfia taibai; \u003c/em\u003eE. \u003cem\u003eAristolochia sieboldii,\u003c/em\u003e host plants of \u003cem\u003eL. chinensis huashanensis\u003c/em\u003e，F. \u003cem\u003eA. manshuriensis, \u003c/em\u003ehost plants of \u003cem\u003eBhutanitis thaidina.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/8d85a60ffeca6a066173d6d9.png"},{"id":85394546,"identity":"26371c2c-aa74-443a-ba45-6e8a6feb91ba","added_by":"auto","created_at":"2025-06-25 10:57:21","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1110299,"visible":true,"origin":"","legend":"\u003cp\u003eForests cover canopy variation in Taibai Mountain from 2000 t0 2023\u003c/p\u003e\n\u003cp\u003eA: 2000, Forests cover canopy 86.11%,; B.2012, Forests cover canopy88.41%,;\u003c/p\u003e\n\u003cp\u003eC: 2023, Forests cover canopy 90.58%\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/eb43606417ed98753912d317.png"},{"id":85396320,"identity":"184e4ae7-67b8-48f3-9982-19b2e29265da","added_by":"auto","created_at":"2025-06-25 11:13:25","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":648539,"visible":true,"origin":"","legend":"\u003cp\u003eThe eggs, larvae, and pupa of (\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e).\u003c/p\u003e\n\u003cp\u003eA.eggs,B.second-instar larva,Cmature larva,D pupa\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/c7ad870b517d8b2ef72595fe.png"},{"id":85394551,"identity":"08b2cac5-0408-4166-8167-6b275077eb7c","added_by":"auto","created_at":"2025-06-25 10:57:22","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":25305,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal Component Analysis of Environmental Factors in Oviposition Sites of Luehdorfia chinensis huashanensis\u003cem\u003e \u003c/em\u003e(X1, X2, X3 in the figure represent altitude, host plant density, and coverage, respectively)\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/98402015d5c48afb42f176f1.png"},{"id":85394545,"identity":"eb478e3c-3f3e-4b09-81d2-287833fd5578","added_by":"auto","created_at":"2025-06-25 10:57:21","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":814981,"visible":true,"origin":"","legend":"\u003cp\u003eAnthropogenic harvesting of the host plant \u003cem\u003eAsarum sieboldii\u003c/em\u003e and Haibitat of \u003cem\u003eL. chinensis huashanensis\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/803a845a79028af941314121.png"},{"id":96624239,"identity":"c0306c5f-44ae-4ee7-a40a-17adffd37b32","added_by":"auto","created_at":"2025-11-24 11:23:38","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5930600,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6780797/v1/e2e9af5f-ec1f-4526-91e0-664fa86c404b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Population trends of three endangered butterflies under the influence of forest restoration and human disturbance in Qinling Mountains","fulltext":[{"header":"Introduction","content":"\u003cp\u003eForests constitute the most critical ecosystem on Earth, providing multidimensional ecosystem services. These include provisioning services such as timber, fiber, food, and medicinal herbs; regulating services encompassing soil conservation, water retention, pollution purification, carbon sequestration and oxygen release; and cultural services like forest aesthetics and ecotourism. Crucially, forests sustain rich biodiversity by offering habitats for wildlife. Research indicates that approximately 80% of terrestrial biodiversity relies on forest ecosystems for survival (Kingdom, 2005).\u003c/p\u003e\n\u003cp\u003eThe accelerated global industrialization has exacerbated over exploitation and irrational utilization of natural resources, leading to habitat fragmentation and loss. These processes manifest as reduced habitat area, intensified edge effects, and isolated habitat patches (Pullin, 2005; Fang \u0026amp; Guan, 2010). Such changes profoundly impact forest-dwelling species, with habitat loss and fragmentation recognized as primary drivers of species extinction. Current extinction rates are estimated to be 100,000 times higher than natural background rates, with approximately 75 species disappearing daily (Wilson, 1993). The IPBES (2019) report reveals that one million species worldwide face extinction threats, with endangered proportions reaching 48% for mammals, 49% for birds, and 64% for amphibians (Wu \u0026amp; Li, 2003). As key components of ecological chains, butterfly population declines may trigger ecosystem cascades (Paine \u0026amp;Robert,1966). Consequently, forest conservation, habitat restoration, and biodiversity maintenance have become urgent global priorities.\u003c/p\u003e\n\u003cp\u003eOver 20,000 butterfly species are documented globally, with China recording more than 1,700 species (Chou, 1999; Wu \u0026amp; Xu, 2017). Butterflies play key roles in ecosystems as pollinators for wild plants, participants in nutrient cycling and energy flow, and organisms with life cycles tightly linked to plant communities (Ollerton et al., 2011; William et al., 1975; Yang \u0026amp; Gratton, 2014). Compared to other insects, butterflies exhibit moderate body size, diurnal activity patterns, and high sensitivity to environmental changes, making them vital bioindicators of ecological health (Thomas, 2005; Liu et al., 2018; Yin et al., 2023). Studies demonstrate their response rates to environmental disturbances such as habitat degradation and climate change exceed those of host plants by 3–30 times (Hu et al., 2010; Maes \u0026amp; Dyck, 2001), establishing them as ideal subjects for biodiversity monitoring and ecological restoration evaluation (Kumar et al., 2009).\u003c/p\u003e\n\u003cp\u003eHabitat restoration impacts butterfly diversity in complex ways. Moderate anthropogenic disturbances like secondary forest management may enhance diversity, while intensive disturbances such as monoculture plantations lead to species homogenization (Vu, 2009; Vu \u0026amp; Vu, 2011). For example, European semi-natural grasslands lost 80% of their area due to excessive mowing, causing drastic butterfly diversity declines, though scientific grazing and reduced mechanical intervention stabilized certain populations (Humbert et al., 2010; Jan et al., 2016; Joanna et al., 2016; Joanna \u0026amp; Piotr, 2023; Joyce \u0026amp; Chris, 2014). Forest restoration similarly demonstrates dual effects: The Karner blue butterfly \u003cem\u003eLycaeides melissa samuelis\u003c/em\u003e became endangered when canopy density exceeded 60%, reducing host plant availability (Grundel et al., 1998), while China’s\u0026nbsp;\u003cem\u003eLuehdorfia taibai\u003c/em\u003e experienced population collapse due to excessive canopy closure in secondary forests (Guo et al., 2014). These cases highlight habitat heterogeneity management as critical for balancing restoration and conservation (Botham et al., 2015; Michael \u0026amp; Kessler, 2000; Rowe et al., 2015).\u003c/p\u003e\n\u003cp\u003eGlobal studies indicate butterfly diversity is influenced by interactions among vegetation structure, climatic conditions, and anthropogenic interventions. In temperate forests, canopy gaps with 30%–60% openness optimize butterfly oviposition and host plant growth (Grundel et al., 1998). Tropical rainforest restoration requires maintaining understory light gradients to support niche-differentiated species (Humbert et al., 2010). Domestic research focuses on endangered species mechanisms, conservation strategies, geographic distribution patterns (Wang et al. 2024), and habitat change impacts. For instance, studies include conservation research on the\u003cem\u003e\u0026nbsp;Luehdorfia Taibai\u003c/em\u003ein\u0026nbsp;Qinling\u0026nbsp;Mountains\u0026nbsp;(Guo et al., 2014), population ecology of the \u003cem\u003eByasa impediens\u0026nbsp;\u003c/em\u003e(Li et al., 2012), and habitat selection of the \u003cem\u003eTeinopalpus aureus\u003c/em\u003e (Yang et al., 2024). Vegetation community stability directly affects butterfly population dynamics, with generalist taxa like Pieridae and Nymphalidae dominating fragmented habitats while habitat specialists decline (Han et al., 2022).\u003c/p\u003e\n\u003cp\u003eThe Qinling Mountains, a biodiversity hotspot in China, harbor over 900 butterfly species (Fang, 2019). Three habitat specialists include the \u003cem\u003eBhutanitis thaidina\u003c/em\u003e and the \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e, both listed as National Grade II Protected Species (He, 1989), and the critically endangered\u0026nbsp;\u003cem\u003eLuehdorfia taibai\u003c/em\u003e. These three species of butterflies belong to habitat-specific species, which have strict requirements for habitat microenvironment and are easily affected by human disturbance and habitat changes.Research conducted in 2011–2012 within Taibai Mountain Nature Reserve identified threats including host plant over harvesting, excessive canopy closure, and climate change (Gao et al., 2013; Guo et al., 2014). Eleven years later, intensified canopy closure and persistent plant harvesting likely altered their survival status. Follow-up surveys from 2023 to 2025 assessed population trends, analyzed threats, evaluated endangerment levels, and proposed conservation strategies. This work aims to enhance governmental and public awareness, promote participatory conservation, and implement science-based measures to ensure these species’ long-term survival.\u003c/p\u003e"},{"header":"1. Research methods","content":"\u003cp\u003e\u003cstrong\u003e1.1 Research species\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e1\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cem\u003eLuehdorfia taibai\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLuehdorfia taibai\u003c/em\u003e, an endemic Chinese species, inhabits shaded, moist areas along mountain streams at elevations of 1000\u0026ndash;1800 m in the Taibai Mountain Nature Reserve, Zhouzhi Nature Reserve, and Xiaolongshan Baihualin Forest Farm of the Qinling Mountains. This univoltine species overwinters as pupae, with adults emerging in mid-to-late April. Adults prefer habitats with stronger illumination, typically inhabiting forest edges or canopy gaps. After emergence and mating, females oviposit on the abaxial surfaces of leaves of the host plant \u003cem\u003eSaruma henryi\u003c/em\u003e, selecting sites with thick litter layers. Larvae feed exclusively on \u003cem\u003eS. henryi\u003c/em\u003e , completing larval development in approximately 40 days before pupating in mid-June, with pupal diapause lasting 280 days (Guo et al., 2014). Figure 1-A,D.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e2\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cem\u003eLuehdorfia chinensis\u003c/em\u003e\u003cem\u003e\u0026nbsp;huashanensis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e, a Qinling Mountains endemic subspecies in China, is categorized as a National Grade II Protected Species under the National Key Protected Wildlife List. This subspecies is distinguished from\u003cem\u003e\u0026nbsp;Luehdorfia chinensis\u0026nbsp;\u003c/em\u003eprimarily by its geographic distribution and host plant specificity. \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e occurs in the central Qinling\u0026apos;s Taibai Mountain Nature Reserve and eastern Huashan region, utilizing \u003cem\u003eAristolochia sieboldii\u003c/em\u003e as its exclusive host plant (Figure 1-B, E). In contrast, the nominate subspecies\u003cem\u003e\u0026nbsp;Luehdorfia chinensis\u003c/em\u003e inhabits the middle-lower Yangtze River basin (Hunan, Jiangsu, and Jiangxi provinces), with \u003cem\u003eAsarum forbesii\u0026nbsp;\u003c/em\u003eserving as its host plant (Yuan et al., 1998; Zou, 2024).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e3\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e inhabits subalpine shrublands and forest edges at elevations of 1092 and 3448 m across the Qinling, Minshan, Hengduan and Shennongjia Mountains, favoring habitats with canopy densities of 0.4\u0026ndash;0.75 (Gao et al.,2013; Lv et al.,2025). This univoltine species overwinters as pupae, with adults active from late May to early July. Adults exhibit strong flight capabilities, engaging in courtship, mating, and nectar-feeding in sunlit areas. Larvae develop for approximately 40 days, feeding exclusively on \u003cem\u003eAristolochia manshuriensis\u003c/em\u003e in Taibai Mountain, where females deposit eggs on the abaxial surfaces of host plant leaves (Gao et al.,2013). Figure 1-C, F.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2 R\u003c/strong\u003e\u003cstrong\u003eesearch site\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in forests surrounding Houzhenzi Town on the southern slope of Taibai Mountain in the Qinling Mountains. As the highest peak of the Qinling range (3,767 m elevation), Taibai Mountain spans Taibai, Mei, and Zhouzhi counties, with geographic coordinates spanning 33\u0026deg;49\u0026apos;\u0026ndash;34\u0026deg;10\u0026apos;N and 107\u0026deg;19\u0026apos;\u0026ndash;107\u0026deg;58\u0026apos;E (Qin et al., 2016). Characterized by cool temperatures and abundant rainfall year-round, the mountain exhibits vertical vegetation zonation comprising deciduous broadleaf forests, coniferous forests, alpine shrublands, and meadow belts from base to summit (Ren et al., 2011). Elevation-dependent climatic zones include temperate monsoon (800\u0026ndash;1,500m), cold-temperate monsoon (1,500\u0026ndash;3,000m), subarctic (3,000\u0026ndash;3,360m), and arctic climates (above 3,360m) (Tang, 2017).\u003c/p\u003e\n\u003cp\u003eQinling\u0026apos;s forests underwent extensive logging from the 1980s to 1990s, leading to reduced canopy coverage, structural simplification, functional degradation, and diminished ecosystem services, negatively impacting wildlife including giant pandas. Since China\u0026apos;s 1998 logging ban and implementation of the Natural Forest Protection Program, forest recovery over two decades has increased canopy coverage and wildlife populations. GIS-based measurements indicate landscape-scale forest coverage increased from 86.11% in 2000 to 90.5% in 2023. Figure 2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3 Field survey method\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e1\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cstrong\u003eBiological\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003echaracteristic\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ebservation of\u0026nbsp;\u003c/strong\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eField observations and semi-wild rearing were combined for study. A 40\u0026times;50 m experimental plot was established using \u003cem\u003eAsarum sieboldii\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003ecultivated by local farmers under forest canopies. After \u003cem\u003eA. sieboldii\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003esprouted in mid-April, gravid females of \u003cem\u003eL. chinensis huashanensis\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003ewere attracted to oviposit. Eggs were tagged on petioles post-oviposition, with records of oviposition dates, egg counts, and daily monitoring to determine hatching dates and egg development duration. Post-hatching, larval feeding, molting, and developmental stages were tracked, including instar durations and prepupal behaviors. Adult flower-visiting and mating behaviors were documented in forest-edge valleys.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003cstrong\u003eLife Table Analysis of\u003c/strong\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eLife table construction identified critical endangerment factors. Egg clusters on host plants were tagged across habitat patches. Regular monitoring recorded population changes in eggs and larvae, mortality rates, causes of death, and prepupal behaviors until pupation. Habitat parameters were systematically logged. Sublethal mortality (*k*) for each factor was calculated as:\u003c/p\u003e\n\u003cp\u003ek = lgN \u0026ndash; lgNs\u003c/p\u003e\n\u003cp\u003ewhere \u003cem\u003eN\u003c/em\u003e = initial population size, \u003cem\u003eN_s\u003c/em\u003e = surviving individuals post-factor exposure.\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e3\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cem\u003eSample survey\u003c/em\u003e\u003cstrong\u003e\u0026nbsp;for Host Plant Density, Egg, and Larval Counts\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe host plants for \u003cem\u003eLuehdorfia taibai\u003c/em\u003e (\u003cem\u003eSaruma henryi\u003c/em\u003e) and \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e (\u003cem\u003eAsarum sieboldii\u003c/em\u003e) are predominantly distributed under forest canopies, with eggs and larvae located on the abaxial leaf surfaces. To survey eggs and larvae, 5\u0026times;5 m sample were randomly established in areas with potential host plant presence. Within each sample, host plant counts and egg/larval numbers per plant were recorded. 22 sample across 5 sites from April to June in \u003cstrong\u003e2012\u003c/strong\u003e were conducted. 26 sample across 3 sites from April to June in \u003cstrong\u003e2023\u0026ndash;2024\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;were conducted\u003c/strong\u003e. For \u003cem\u003eBhutanitis thaidina\u003c/em\u003e (host plant: \u003cem\u003eAristolochia manshuriensis\u003c/em\u003e), surveys focused on cliff faces and rocky gaps: 31 sample(5\u0026times;5 m ) across 4 sites from May to July were conducted in 2023\u0026ndash;2024 and compared with 27 sample across 8 sites in 2012 were conducted.\u003c/p\u003e\n\u003cp\u003e（4）\u003cstrong\u003eAdult Population Surveys\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTransects (5\u0026times;500\u0026ndash;2000 m) were established in high-elevation valleys, streams, forest edges, or canopy gaps (canopy density \u0026lt;0.6). Transect parameters (altitude, coordinates, vegetation cover) and observed adults, nectar plants, and anthropogenic disturbances were recorded. \u003cem\u003eL.taibai\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003eand \u003cem\u003eL.\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003cem\u003echinensis huashanensis\u003c/em\u003e: 4 times surveys (April\u0026ndash;May 2012; April\u0026ndash;May 2023\u0026ndash;2025). \u003cem\u003eB. thaidina\u003c/em\u003e\u003cem\u003e:\u003c/em\u003e 2 surveys May\u0026ndash;July 2023\u0026ndash;2024).\u003c/p\u003e\n\u003cp\u003e（5）\u003cstrong\u003eData Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKey metrics:\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHost plant density\u003c/strong\u003e: Total plants / sample area (m\u0026sup2;).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInfested plant rate\u003c/strong\u003e: (Infested plants / total plants) \u0026times; 100%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLarval density per plant\u003c/strong\u003e: Total larvae / total plants.\u003c/p\u003e\n\u003cp\u003eFor \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e, anthropogenic threats (host plant harvesting for traditional medicine) were analyzed using infested plant rate as the response variable. Predictors included altitude (\u003cem\u003eX₁\u003c/em\u003e), host plant density (\u003cem\u003eX₂\u003c/em\u003e), and forest cover (\u003cem\u003eX₃\u003c/em\u003e). Principal Component Analysis (PCA) addressed multicollinearity, followed by regression modeling to quantify variable relationships.\u003c/p\u003e"},{"header":"2.\tResearch results","content":"\u003cp\u003e\u003cstrong\u003e2.1.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ePopulation Trends of\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eLuehdorfia taibai\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eDuring 2011\u0026ndash;2012, 22 sample with 5\u0026times;5 m were surveyed in understory and forest-edge habitats near Houzhenzi Town on Taibai Mountain\u0026rsquo;s southern slope, within the elevational range of 1,073\u0026ndash;1,589 m. These sample exhibited an average forest cover of 67.27%, with host plant\u0026nbsp;\u003cem\u003eSaruma henryi\u003c/em\u003edensity averaging 2.22 plants/m\u0026sup2;. Egg clusters were detected on 55% of host plants, averaging 17.16 eggs per clutch (Guo et al., 2014).\u0026nbsp;In 2023\u0026ndash;2024, surveys 26\u0026nbsp;sample with\u0026nbsp;5\u0026times;5 m (elevation: 1,004\u0026ndash;1,498 m) revealed a 73.08% average forest cover\u0026nbsp;canopy\u0026nbsp;but a drastic 94.2% decline in host plant density to 0.13 plants/m\u0026sup2; (Appendix 1). No eggs or larvae were recorded. Follow-up 2025 surveys of 4\u0026nbsp;sample\u0026nbsp;showed marginally higher host plant density (0.48 plants/m\u0026sup2;, Appendix 1-2), yet still no eggs or larvae were observed.This trajectory demonstrates that increasing forest cover (resulting in canopy closure and loss of sunlit gaps) has directly reduced suitable habitats for\u0026nbsp;\u003cem\u003eLuehdorfia taibai\u003c/em\u003e, triggering host plant depletion and subsequent population collapse. The complete absence of reproductive indicators (eggs/larvae) in recent surveys suggests local extirpation risks under current forest succession patterns.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eLife History and Threat Factors of\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eLuehdorfia chinensis huashanensis\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.1\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eBehavioral Ecology of\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eLuehdorfia chinensis huashanensis\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003eis distributed in the Taibai Mountain region at elevations above 1,600 m, with population concentrations between 1,800\u0026ndash;2,000 m. This subspecies exhibits a univoltine life cycle, overwintering as pupae and emerging as adults in mid-to-late April. Adults demonstrate strong flight capabilities, traveling considerable distances to locate nectar sources and host plants, primarily foraging on\u0026nbsp;\u003cem\u003eCerasus\u003c/em\u003especies (Rosaceae), and favoring sunlit, moderately dry microhabitats at forest edges. Males employ a patrolling mating strategy, pursuing females until mating acceptance. Post-copulation, females develop a brown chitinous shield (~5 mm diameter) at the genital opening to prevent subsequent mating attempts. Eggs are deposited in clusters on the abaxial surfaces of the host plant\u0026nbsp;\u003cem\u003eAristolochia sieboldii\u003c/em\u003e(Figure 3-A), typically containing 6\u0026ndash;14 eggs per cluster (rarely singly), spaced ~1 mm apart, with \u0026le;2 clusters per leaf. Eggs are subglobose (1.0 mm diameter), initially pale green with pearlescent luster, transitioning to translucent white prior to hatching, with larval head capsules visible through the chorion. Egg development spans 12\u0026ndash;14 days, extendable under prolonged rainfall\u003c/p\u003e\n\u003cp\u003eLarvae undergo five instars: newly hatched larvae exhibit black heads, brown bodies, and fine setae, remaining gregarious until the third instar, often aligning linearly when resting (Figure 3-B). Post-third instar, larvae disperse and exhibit nocturnal feeding patterns, hiding beneath host plant roots or leaf litter during daylight and rapidly everting osmeteria when disturbed. The larval stage lasts ~40 days, with extended duration during the fifth instar. Mature larvae (Figure 3-C) pupate within leaf litter or rock crevices, securing themselves via silk threads during a 2\u0026ndash;3 day prepupal stage. Pupae are suspensory, dark brown, rigid, and texturally rugose (Figure 3-D), undergoing diapause for ~280 days.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.2\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Life table of the\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eLuehdorfia chinensis huashanensis\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLarval mortality is primarily influenced by anthropogenic harvesting of its host plant\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cem\u003eAsarum sieboldii\u003c/em\u003e\u003cstrong\u003e, secondarily associated with rain scouring, natural enemies (predominantly spiders and ants), and diseases. Population life table data are presented in Table 1.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable\u0026nbsp;1\u0026nbsp;Life Table of\u0026nbsp;Larvae Population of\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e in Taibai Mountain （April to Jun 2012）\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;Develop stage\u0026nbsp;x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003ePopulation count\u0026nbsp;lx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eCause of mortality\u0026nbsp;dxF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003eMortality count\u0026nbsp;dx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003eMortality rate\u0026nbsp;100qx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003eSurvival rate\u0026nbsp;100sx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 68px;\"\u003e\n \u003cp\u003eEggs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e106\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e36.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e63.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eUnhatched\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e7.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e92.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ek1= 0.1992\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eMortality due to anthropogenic harvesting of host plants\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e29.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e70.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ek2= 0.03408\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e1st\u0026ndash;3rd instar larvae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e82.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e17.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eRainfall\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e22.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e77.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK3=0.1101\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eMortality due to bacterial infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e4.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e95.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK4=0.01990\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003ePredation by natural enemies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e23.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e76.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK5=0.1185\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003eMortality due to anthropogenic harvesting of host plants\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e31.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e68.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK6=0.1633\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;4th\u0026ndash;5th instar larvae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003ePredation by natural enemies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e8.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e91.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eK7=0.03779\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003ePupa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 82px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1 demonstrates that anthropogenic harvesting of host plants exerted the highest impact during the 1st\u0026ndash;3rd instar larval stage (k₆ = 0.1633), followed by predation from natural enemies (k = 0.1185).\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.3\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eImpact of Anthropogenic Harvesting of Host Plants (\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eAsarum sieboldii\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e) on Population Viability of\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eLuehdorfia chinensis huashanensis\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e（1）\u003cstrong\u003eOviposition Site Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalysis of oviposition site selection revealed significant correlations between elevation (\u003cem\u003eX₁\u003c/em\u003e) and host plant density (\u003cem\u003eX₂\u003c/em\u003e) (Figure 4). Principal Component Analysis (PCA) of 2012 survey data extracted two principal components (cumulative contribution rate: 83.9%). The derived regression equation after coefficient transformation was:y= 3.041513431+0.002297815 -0.016266396-0.061687671。This indicates that within suitable habitats, oviposition frequency of \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e increases with higher elevation (\u003cem\u003eX₁\u003c/em\u003e), elevated host plant density (\u003cem\u003eX₂\u003c/em\u003e), and reduced forest cover (\u003cem\u003eX₃\u003c/em\u003e) (\u003cem\u003eF\u003c/em\u003e = 7.998, *p* = 0.006). Semi-wild rearing environments with artificially enhanced host plant density also elicited oviposition behavior. Notably, infested plant rates dropped to 0% in areas experiencing host plant harvesting. Destructive harvesting practices have caused localized extirpation of \u003cem\u003eAsarum sieboldii\u003c/em\u003e populations in habitats such as Qingshuihe valey.\u003c/p\u003e\n\u003cp\u003e（2）\u003cstrong\u003ePopulation Trends and Endangerment Mechanisms of\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe host plant \u003cem\u003eAsarum sieboldii\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e(Figure 5-B), a medicinal herb subjected to intensive harvesting due to high market demand (Figure 5-A), thrives in forest understories.\u003c/p\u003e\n\u003cp\u003eBased on the presence/absence of eggs or larvae in 2023\u0026ndash;2024 surveys, sample were classified as \u0026quot;occupied\u0026quot; (host plants with eggs/larvae) or \u0026quot;unoccupied\u0026quot; (host plants only). Comparative analyses revealed no significant differences between occupied and unoccupied sample in elevation (*t*\u0026nbsp;= -0.055,\u0026nbsp;*p*\u0026nbsp;\u0026gt; 0.05), canopy density (*t*\u0026nbsp;= 0.803,\u0026nbsp;*p*\u0026nbsp;\u0026gt; 0.05), or host plant density (*t*\u0026nbsp;= 1.689,\u0026nbsp;*p*\u0026nbsp;\u0026gt; 0.05), indicating habitat homogeneity across these parameters.\u003c/p\u003e\n\u003cp\u003eLongitudinal analysis (11-year interval) quantified host plant decline. 20 sampling in 2011-2012 shows averaged 89.5% forest cover canopy, with \u003cem\u003eA. sieboldii\u003c/em\u003e density of 2.79 plants/m\u0026sup2; and larval density of 3.16 larvae/plant (Appendix 2-1).34 sampling in 2023-2024 showed a 71.33% reduction in host plant density (0.856 plants/m\u0026sup2;) and a 95.03% decline in larval density (0.18 larvae/plant) (Appendix 2-2). This precipitous decline correlates directly with anthropogenic harvesting pressure and habitat homogenization, underscoring the subspecies\u0026apos; critical endangerment status.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ePopulation Trends of\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGao et al. (2014) reported a host plant density of 0.406 plants/m\u0026sup2; and an larvae infested plant rate of 5.29% across 32 sampling surveyed during 2011\u0026ndash;2012. In 2023\u0026ndash;2024, resurveys of 28 sampling in the same locations revealed a 65.52% decline in host plant density (0.14 plants/m\u0026sup2;) and a 43.29% reduction in infested plant rate (0.003 larvae/plant) (Appendix 3). These findings correlate with rising forest coverage, demonstrating significant adverse impacts on\u0026nbsp;\u003cstrong\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003esurvival through concurrent declines in host plant availability and larval populations.\u003c/p\u003e"},{"header":"3. Discussion","content":"\u003cp\u003e\u003cstrong\u003e3.1\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eSurvival Status of the Three Butterfly Species\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLongitudinal surveys spanning 11 years revealed critical declines across all three species:\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eLuehdorfia taibai\u003c/em\u003e\u003c/strong\u003e: No adults, eggs, or larvae were detected during 2023\u0026ndash;2025 surveys in historical habitats, indicating potential local extinction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003c/strong\u003e: Host plant (\u003cem\u003eAsarum sieboldii\u003c/em\u003e) density declined by 71.33%, accompanied by a 37.03% reduction in larvae infested plant rate, signaling marked population contraction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e\u003c/strong\u003e: Host plant (\u003cem\u003eAristolochia manshuriensis\u003c/em\u003e) density decreased by 65.52%, with a 43.29% decline in larvae infested plant rate.\u003c/p\u003e\n\u003cp\u003eThese trends correlate strongly with anthropogenically driven forest succession, which eliminates critical open-canopy microhabitats and disrupts host plant availability.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eAnalysis of Endangerment\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eFactor\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePopulation declines and local extinctions of the three butterfly species exhibit significant correlation with host plant depletion (\u003cem\u003eR\u0026sup2;\u003c/em\u003e = 0.72, *p* \u0026lt; 0.01), supporting the \u0026quot;co-extinction hypothesis\u0026quot; (Ehrlich \u0026amp; Raven, 1964). This posits that plants and insects form interdependent networks through complex interactions (e.g., defense, mutualism, resource competition), where extinction of one may cascade to the other via ecological linkages.\u003c/p\u003e\n\u003cp\u003e（1）\u003cstrong\u003eEndangerment Mechanisms of\u003c/strong\u003e\u003cem\u003eLuehdorfia taibai\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eImplementation of China\u0026rsquo;s Natural Forest Protection Program restored forest canopy density from 86.11% (2000) to 90.58% (2023), eliminating critical sunlit gaps. Resultant understory light and thermal insufficiency suppressed host plant \u003cem\u003eSaruma henryi\u003c/em\u003egrowth, reducing density from 2.23 to 0.13 plants/ m\u0026sup2; (*p*\u0026nbsp;\u0026lt; 0.01). Dense canopies further impeded adult flight and oviposition behaviors.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e2\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cstrong\u003eEndangerment Mechanisms of\u003c/strong\u003e\u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eHarvesting of host plants is thought to be the main cause of its decline. With the increase of market demand, the price of the host plant \u003cem\u003eAsarum sieboldii\u003c/em\u003e, which is used as a Chinese herbal medicine, has risen from 120 CNY/kg in 2012 to 400 CNY/kg in 2024. Driven by economic interests, mining intensified, and host plant density decreased by 64%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMicrohabitat degradation\u003c/strong\u003e: Increased canopy density reduced understory light availability, impairing \u003cem\u003eA. sieboldii\u003c/em\u003egrowth and larval development while hindering adult oviposition.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e（\u003c/em\u003e\u003cem\u003e3\u003c/em\u003e\u003cem\u003e）\u003c/em\u003e\u003cstrong\u003eEndangerment Mechanisms of\u003c/strong\u003e\u003cem\u003eBhutanitis thaidina\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCanopy closure\u003c/strong\u003e: Loss of forest gaps restricted adult movement and oviposition, while understory thermal deficits delayed larval development.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInterspecific competition\u003c/strong\u003e: Intensified resource competition with \u003cem\u003eByasa polyeuctes\u003c/em\u003e, a numerically dominant congener sharing\u0026nbsp;\u003cem\u003eAristolochia manshuriensis\u003c/em\u003e(Guo et al., 2014; Lv et al., 2025).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePredation pressure\u003c/strong\u003e:\u0026nbsp;Larval mortality exceeded 90% due to diverse forest predators (Guo et al., 2014).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClimate-driven range shifts\u003c/strong\u003e: Upward elevational migration of adults outpaced host plant colonization, limiting successful establishment (Lv et al., 2025).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eConservation Strategies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003cstrong\u003eHabitat Management\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eImplement targeted forest management in native habitats of \u003cem\u003eLuehdorfia taibai\u003c/em\u003e, \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e, and \u003cem\u003eBhutanitis thaidina\u003c/em\u003e. Key interventions include periodic canopy thinning, coppicing, shrub clearance, and replanting host plants to restore understory environments conducive to host plant growth and adult activity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003cstrong\u003eHost Plant Protection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInclude host plants of all three species (\u003cem\u003eSaruma henryi\u003c/em\u003e, \u003cem\u003eAsarum sieboldii\u003c/em\u003e, and \u003cem\u003eAristolochia manshuriensis\u003c/em\u003e) in the National Key Protected Plant List to curb illegal harvesting, ensuring simultaneous protection of plants and butterflies.\u003c/p\u003e\n\u003cp\u003e（3）\u003cstrong\u003eIn Situ Captive Breeding and Population Recovery\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEstablish conservation bases near extant habitats, replicating natural conditions (light intensity \u0026gt;2000 lux, canopy density 40%\u0026ndash;60%). Cultivate host plants and nectar sources to attract ovipositing adults, enhance larval development, and boost population numbers (Guo et al., 2014).\u003c/p\u003e\n\u003cp\u003e（4）\u003cstrong\u003ePublic Education Campaigns\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDistribute conservation pamphlets highlighting butterfly ecological importance and risks of Aristolochiaceae plants (containing carcinogenic aristolochic acid). Discourage public use of these plants in traditional medicine and culinary practices.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003eWe are sincerely grateful to Dr. Ruikun Gou who works for\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNorthwest F\u0026amp;F University take the Arc GIS Analysis on forest cover canopy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003eLZ: conducted field work from 2023-2024 and wrote the main\u0026nbsp;\u003c/p\u003e\n\u003cp\u003emanuscript text. ZG: conducted field work from 2011-2012. XL: designed the research framework and revised the manuscript text. YX: conducted the field work. YZ: revised the manuscript. JS: revised the manuscript. All authors reviewed the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eNational Key R and D Program of China, 2022YFE0115200, Scientifc Research initial project of CWNU, 20E064.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003eNo datasets were generated or analyzed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBotham MS, Fernandez-Ploquin EC, Brereton T, Harrower CA, Roy DB, \u0026amp; Heard MS (2015) Lepidoptera communities across an agricultural gradient: how important are habitat area and habitat diversity in supporting high diversity? \u003cem\u003eJournal of Insect Conservation\u003c/em\u003e, 19(2), 403-420.\u003c/li\u003e\n\u003cli\u003eChou I (1999) Monograph of Chinese butterflflies. Henan Scientifific and Technological Publishing House, Henan (in Chinese)\u003c/li\u003e\n\u003cli\u003eEhrlich PR, \u0026amp; Raven PH (1964) Butterflies and Plants: A Study in Coevolution. \u003cem\u003eEvolution\u003c/em\u003e, 18(4), 586-608.\u003c/li\u003e\n\u003cli\u003eFang L, \u0026amp; Guan J (2010) Responses of butterflies to global climate change and research progress. \u003cem\u003eJournal of Environmental Entomology\u003c/em\u003e, 32(3), 9..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eFang L（2024）The Butterfly Chronicles of the Great Qinling, Xi\u0026apos;an Publishing House \u003c/li\u003e\n\u003cli\u003eGao K (2013) \u003cem\u003eStudy on the endangered mechanisms and conservation of Bhutanitis thaidina (Blanchard) in Taibai Mountain region\u003c/em\u003e [Master\u0026rsquo;s thesis, Northwest A\u0026amp;F University]. CNKI. https://link.cnki.net/doi/10.27409/d.cnki.gxbnu.2013.000108.(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eGrundel R, Pavlovic NB, \u0026amp; Sulzman CL (1998) Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover. \u003cem\u003eBiological Conservation\u003c/em\u003e, 85(1), 47-53.\u003c/li\u003e\n\u003cli\u003eGuo Z, Gao K, Li X, \u0026amp; Zhang Y (2014) Biology and habitat research of the \u003cem\u003eLuedorfia \u003c/em\u003e\u003cem\u003eTaibai\u003c/em\u003e. \u003cem\u003eActa Ecologica Sinica\u003c/em\u003e, *34*(23), 6943\u0026ndash;6953..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eHan D, Wang C, Sun Z, She J, Yin L, Bian Q, \u0026amp; Han W (2022) Microhabitat preferences of butterflies in urban parks: both vegetation structure and resources are decisive. \u003cem\u003eUrban Forestry \u0026amp;Amp; Urban Greening\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003eHu B, Li H, Zhipin L, \u0026amp; Tiejian Z (2010) Diversity and fauna of butterflies in Baxian Mountain State Nature Reserves. \u003cem\u003eActa Ecologica Sinica\u003c/em\u003e, 30(12), 3226-3238.\u003c/li\u003e\n\u003cli\u003eHumbert JY, Ghazoul J, Sauter GJ, \u0026amp; Walter T (2010) Impact of different meadow mowing techniques on field invertebrates. \u003cem\u003eJournal of Applied Entomology\u003c/em\u003e(7), 134.\u003c/li\u003e\n\u003cli\u003eIPBES report: Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.Publication | 2019\u003c/li\u003e\n\u003cli\u003eJan, Christian, Habel, Mike, Teucher, Werner, Ulrich, Markus, Bauer, \u0026amp; Dennis (2016) Drones for butterfly conservation: larval habitat assessment with an unmanned aerial vehicle. \u003cem\u003eLandscape Ecology\u003c/em\u003e, 31(10), 2385-2395.\u003c/li\u003e\n\u003cli\u003eJoanna KB, Piotr S, Piotr N, Maciej B, Aw KW, Damian SY, Michal W, \u0026amp; Banks SC (2016) Relative Contribution of Matrix Structure, Patch Resources and Management to the Local Densities of Two Large Blue Butterfly Species. \u003cem\u003ePlos One\u003c/em\u003e, 11(12), e168679.\u003c/li\u003e\n\u003cli\u003eJoanna K, \u0026amp; Piotr N (2023) Vanishing meadows \u0026mdash; Quantitative analysis of factors driving population declines of endangered butterflies. \u003cem\u003eBiological Conservation\u003c/em\u003e, 282\u003c/li\u003e\n\u003cli\u003eJoyce, \u0026amp; Chris B (2014) Ecological consequences and restoration potential of abandoned wet grasslands. \u003cem\u003eEcological Engineering\u003c/em\u003e, 66, 91-102.\u003c/li\u003e\n\u003cli\u003eKingdom U (2005) Global Forest Resources Assessment 2020\u003c/li\u003e\n\u003cli\u003eKumar S, Simonson SE, \u0026amp; Stohlgren TJ (2009) Effects of spatial heterogeneity on butterfly species richness in Rocky Mountain National Park, CO, USA. \u003cem\u003eBiodiversity \u0026amp; Conservation\u003c/em\u003e, 18(3), 739-763.\u003c/li\u003e\n\u003cli\u003eLi X, Zhang Y, Settele J, Franzen M and Schweiger O (2012) Long-distance dispersal and habitat use of the butterflfly Byasa impediens in a fragmented subtropical forest.Insect Conservation and Diversity (2012) doi: 10.1111/j.1752-4598.2012.00199.x\u003c/li\u003e\n\u003cli\u003eLiu N, Liu Z., Yu L, Zhang Y, Chu J, Yin RC, \u0026amp; Fang J (2018) Species diversity and faunal composition of butterflies in Yaoluoping National Nature Reserve. \u003cem\u003eGenomics and Applied Biology\u003c/em\u003e, *37*(5), 6..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eLv F, Li X, Zhang L, Chang X, Zuo X (2025)Distribution, Habitat Preferences, and Threat Factors of theButterfly \u003cem\u003eBhutanitis thaidina.\u003c/em\u003eDOI : 10.1007/s10841-025-00677-5\u003c/li\u003e\n\u003cli\u003eMaes D, \u0026amp; Dyck HV (2001) Butterfly diversity loss in Flanders (north Belgium): Europe\u0026apos;s worst case scenario? \u003cem\u003eBiological Conservation\u003c/em\u003e, 99(3), 263-276.\u003c/li\u003e\n\u003cli\u003eMichael \u0026amp; Kessler (2000) Elevational gradients in species richness and endemism of selected plant groups in the central Bolivian Andes. \u003cem\u003ePlant Ecology\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003eOllerton J, Winfree R, \u0026amp; Tarrant S (2011) How many flowering plants are pollinated by animals? \u003cem\u003eOikos\u003c/em\u003e, 120(3)\u003c/li\u003e\n\u003cli\u003ePullin AS (2005) \u003cem\u003eConservation biology\u003c/em\u003e (Chinese ed.). Beijing: Science Press. (in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003ePaine, \u0026amp; Robert T (1966). Food Web Complexity and Species Diversity. \u003cem\u003eAmerican Naturalist\u003c/em\u003e, 100(910), 65-75.\u003c/li\u003e\n\u003cli\u003eQin J, Bai H, Li S, Wang J, Gan Z, \u0026amp; Huang A (2016) Differential responses of \u003cem\u003eLarix chinensis\u003c/em\u003e at the alpine timberline on the northern and southern slopes of Taibai Mountain to climate change. \u003cem\u003eActa Ecologica Sinica\u003c/em\u003e, *36*(17), 5333\u0026ndash;5342..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eRen X , Yang G, Wang D, Qin X, Liu Z, Zhao S, Bai Y, Ren X, Yang G, \u0026amp; Wang D (2011) Study on the minimum sampling area of shrub and herb layers in several plant communities in Taibai Mountain. \u003cem\u003eActa Botanica Boreali-Occidentalia Sinica\u003c/em\u003e, *31*(5), 8..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eTang H (2017) \u003cem\u003eTaibai County Annals: 1990\u0026ndash;2010\u003c/em\u003e..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eThomas JA (2005) Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups. \u003cem\u003ePhilosophical Transactions of the Royal Society B Biological Sciences\u003c/em\u003e, 360(1454), 339-357.\u003c/li\u003e\n\u003cli\u003eVu LV (2009) Diversity and similarity of butterfly communities in five different habitat types at Tam Dao National Park, Vietnam. \u003cem\u003eJournal of Zoology\u003c/em\u003e, 277\u003c/li\u003e\n\u003cli\u003eVu LV, \u0026amp; Vu CQ (2011) Diversity Pattern of Butterfly Communities (Lepidoptera, Papilionoidae) in Different Habitat Types in a Tropical Rain Forest of Southern Vietnam. \u003cem\u003eIsrn Zoology\u003c/em\u003e, (1)\u003c/li\u003e\n\u003cli\u003eWang D, Zhang Y, Lu L, Li S \u0026amp; Wang R (2024) Butterfly Diversity Patterns Provide New Insights Into Biodiversity Conservation in China.Global Ecology and Biogeography, 34(1), e13946-e13946.\u003c/li\u003e\n\u003cli\u003eWilliam J, Mattson, Norton D, \u0026amp; Addy (1975) Phytophagous Insects as Regulators of Forest Primary Production. \u003cem\u003eScience\u003c/em\u003e, 190(4214), 515-522.\u003c/li\u003e\n\u003cli\u003eWilson EO (1993) \u003cem\u003eThe Diversity of Life\u003c/em\u003e. Macmillan.\u003c/li\u003e\n\u003cli\u003eWu CS, Xu YF (2017) Butterflies of China. Straits Publishing House.\u003c/li\u003e\n\u003cli\u003eYang L, \u0026amp; Gratton C (2014) Insects as drivers of ecosystem processes - ScienceDirect. \u003cem\u003eCurrent Opinion in Insect Science\u003c/em\u003e, 2, 26-32.\u003c/li\u003e\n\u003cli\u003eYang W, He G, Huang C, Zhou S, Jia F, Zeng J (2024) Application of noninvasive sampling technique in mitochondrial genome intraspecific phylogeny of the endangered butterfly, \u003cem\u003eTeinopalpus aureus \u003c/em\u003e(Lepidoptera: Papilionidae), Insect Science, 24(1):16;1-12. \u003c/li\u003e\n\u003cli\u003eYin J, Shi W, Wang L, Wang Y, Li C, He Q, \u0026amp; Yi C (2023) Study on the community structure and species diversity of butterflies in Yuanyang County, Yunnan Province. \u003cem\u003eJournal of Yunnan Agricultural University (Natural Science)\u003c/em\u003e, *38*(5), 771\u0026ndash;778..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eYuan D, Mai G, Xue D, Hu C, \u0026amp; Ye G (1998) Habitat, biology, and conservation status of the Chinese tiger swallowtail butterfly (\u003cem\u003eLuehdorfia chinensis\u003c/em\u003e). \u003cem\u003eBiodiversity Science\u003c/em\u003e, *6*(2), 105\u0026ndash;115..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eZou M (2024) \u003cem\u003eStudy on the limiting effects of the host plant Asarum forbesii on the Taohongling population of Luehdorfia chinensis and its growth conditions\u003c/em\u003e [Master\u0026rsquo;s thesis, Jiangxi Agricultural University]..(in Chinese with English abstract)\u003c/li\u003e\n\u003cli\u003eSandra D\u0026iacute;az, Josef Brondizio Co Settele , Eduardo Chairs GA.Global Assessment Report on Biodiversity and Ecosystem Services \u0026ndash; Implications for the Global Biodiversity Framework.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Forest restoration, Endangered butterflies; Population trends, Threat factors, Protective measures","lastPublishedDoi":"10.21203/rs.3.rs-6780797/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6780797/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn order to explore the impact of forest restoration on butterfly survival, the long-term changes in the number of butterfly host plants and larvae were investigated by sample survey from 2011 to 2025, and the threat factors were analyzed. Threat factors were provided. The results showed that the number of host plants and larvae of the three specialist butterflies, namely the \u003cem\u003eLuehdorfia taibai\u003c/em\u003e, \u003cem\u003eLuehdorfia chinensis huashanensis\u003c/em\u003e, \u003cem\u003eBhutanitis thaidina\u003c/em\u003e decreased to varying degrees. Among them, the density of the host plant of \u003cem\u003eLuehdorfia taibai\u003c/em\u003edecreased from 2.23 plants/㎡ in 2011 to 0.13 plants/㎡ in 2023, and no eggs and larvae were found in 2023-2025. The density of the host plant of the \u003cem\u003eLuehdorfia chinensis huashanensis \u003c/em\u003edecreased by 71.33%, and the average insect plant rate decreased by 37.03%. The density of host plants of \u003cem\u003eBhutanitis thaidina\u003c/em\u003e decreased by 65.52%, and the rate of insect plants decreased by 43.29%. The main reason for the decline is that the forest is too dense, which leads to the disappearance of glades, the dense forest restricts the oviposition of adults, and the lack of heat under the forest affects the development of larvae. Artificial excavation leads to insufficient number of host plants, and the larvae on the leaves are sunburned. In addition, there is interspecific competition, predation by natural predators, climate change, etc. Population conservation and restoration strategies include habitat management, protection of host plants, in-situ artificial culture, and public education.\u003c/p\u003e","manuscriptTitle":"Population trends of three endangered butterflies under the influence of forest restoration and human disturbance in Qinling Mountains","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-25 10:57:16","doi":"10.21203/rs.3.rs-6780797/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ca615658-44a8-498e-b0b7-05b47a34cd42","owner":[],"postedDate":"June 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-11-24T11:23:15+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-25 10:57:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6780797","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6780797","identity":"rs-6780797","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}