Oecophylla smaragdina (Hymenoptera: Formicidae): A Biological Control Agent of the Invasive Bagworms Metisa plana (Lepidoptera: Psychidae)

Oecophylla smaragdina (Hymenoptera: Formicidae): A Biological Control Agent of the Invasive Bagworms Metisa plana (Lepidoptera: Psychidae) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Oecophylla smaragdina (Hymenoptera: Formicidae): A Biological Control Agent of the Invasive Bagworms Metisa plana (Lepidoptera: Psychidae) Moïse Pierre Exélis, Ramli Rosli, Roslinazairimah Zakaria, Azarae Hj Idris, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7215952/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The invasive bagworm Metisa plana Walker (Lepidoptera: Psychidae) is the dominant pest defoliator of oil palm canopies, leading to substantial leaf damage and monthly yield losses of up to 43%. Standard control methods involved trunk chemical injection (TCI) and spraying of highly toxic pesticides (such as cypermethrin) affecting non-target species. We hypothesized that the introduction of a biological control agent (BCA), the Asian weaver ant ( Oecophylla smaragdina F.) (Hymenoptera: Formicidae), would outperform the TCI in scale and revenue consistency by controlling the bagworm population. A BCA colony was introduced with 20 brood nests translocated into four-hectare allocated experimental plots in Felda plantations, Peninsular Malaysia. To address the nuisances caused by BCA bites, we hypothesized that the essential tea tree oil (TTO) ( Melaleuca linariifolia var. alternifolia ) (Myrtales: Myrtaceae) repellency properties are a potent preventive measure. The assessment of ant-occupied palm trees shows an absence of foliar injury with higher quality fresh fruit bunches (FFB) and oil extraction rate (OER), contrasting with the high bagworm density in unoccupied, critically damaged canopies. BCA stands out as the most productive and lucrative, with more than triple the annual yield, incomes of any TCI group. Given the high correlation between yield variables and income, the polynomial regression showed accuracy in modeling BCA and TCI with minimal deviation between actual and predicted annual income. The repellent effect of TTO instantly neutralizes weaver ant aggressiveness, having an hour long lasting effect (first breakthrough report). Our findings suggest that O. smaragdina is an effective alternative to pesticide control treatment of bagworms. Asian weaver ant quarantine bagworm biological control higher yield Melaleuca alternifolia repellent Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction Playing a significant role as indigenous leaf-eating pests of the African oil palms ( Elaeis guineensis ) Jacq. (Arecales: Arecaceae), in Malaysia and Indonesia (Kamarudin et al., 1994), the bagworm, Metisa plana Walker, is identified as the most dominant destructive pest species (Ting et al., 2023 ; Syarif et al., 2023 ). The defoliation induces a decrease in photosynthesis rate, hence lowering monthly and yearly yield production (Enting & Latip, 2021 ), reaching a fresh fruit bunches (FFB) average loss of 10 tons per acre (Kalidas, 2012 ). Moderate defoliation (10–13%) by bagworms can result in a 30–40% decrease in yield (Mohd Johari et al ., 2023), but more severe infestations can cause up to 43% yield loss (Adhawiyah et al., 2023 ; Basri et al., 2022 ). The economic losses exceeded USD 25 million yearly (Che Hussian et al., 2025 ). Thus, the damage caused by the invasive M. plana species is likely to become more widespread without proper control measures (Wood & Norman, 2019a ; Wood & Norman, 2019b ). In 2013, bagworms were officially classified as quarantine pests in Malaysia (Kamarudin et al., 2017 ). To eliminate this pest, broad-spectrum, long-lasting contact pesticides (Cypermethrin and deltamethrin are highly toxic) have been used (Wood & Norman, 2019a ). This led to an ecological disaster, marked by the indiscriminate suppression of beneficial insects and the accumulation of chemical hazards in agricultural soils and the environment, contributing to the development of pesticide resistance among target species (Wood & Norman, 2019b ). An alternative, cheap, and environmentally friendly method of control is necessary. The Asian weaver ant ( Oecophylla smaragdina F.) has controlled over 50 pest species across 12 diverse crops (Way & Khoo, 1992 ; Peng et al., 2012a ). Its effectiveness as a biological control agent has been compared with pesticides in Southeast Asia and Australia (Van Mele & Cuc, 2000 ; Peng & Christian, 2005a ). Bagworm infestations are critical in unoccupied weaver ant palms (Exélis & Idris, 2013 ). In unoccupied plantations, collected brood nests are translocated to rear incipient colonies in the outbreak-affected plants (Offenberg et al., 2013 ). Introducing new nests to boost incipient colonies in affected areas is a documented effective method (Exélis et al., 2023a , b). The ants' major workers engage in daily predation through extensive foraging and territorial behaviour (Exélis et al., 2024 ; Exélis et al., 2025a ). Their bites, resulting in the rejection of using Asian weaver ants as a biological control agent (BCA) in some cases (Van Mele, 2008 ; Van Mele et al., 2009 ; Offenberg, 2015 ). Some plantation workers even resorted to burning ants’ nests or exterminating them with poisons (Exélis et al., 2023a ). Therefore, we propose and hypothesize that the tea tree ( Melaleuca linariifolia var. alternifolia (Maiden & Betche) essential oil is a potential repellent of weaver ants (Chailleux et al., 2019 ). Assuming an output shows a high R² (variance proportion) and relatively low Root Mean Squared Error (RMSE), we hypothesized that the combination of Average Yield, Oil Extraction Rate (OER), and Total Yield can successfully predict income with some nonlinear adjustments using a polynomial regression. This study assesses (1) the ability of weaver ants to control bagworm populations by comparison with the trunk chemical injection (TCI) method. The efficiency levels were measured based on various productivity parameters, i.e., foliar injury level, monthly fresh fruit bunches (FFB) yield, and OER relating to grade quality. In addition, we assess (2) the effectiveness of the tea tree oil (TTO) essential oil as a treatment for (i) bite protection, (ii) repelling the Asian weaver ant, and (iii) determining their long-lasting effect. 2. Materials and Methods 2.1. Study sites and plot selection This study was conducted in oil palm plantations located in Felda Gunung Besout, Perak, Malaysia, from 2019–2022 (N03°49.408’ E101°19.775’ and 3°50’30” 101°18’08” E; Supplementary Fig. 1). The total plantation's area is 1064.53 ha, and it was further divided into 4-ha plots allocated to 266 smallholders. The oil palm plots were selected based on: (1) the presence of bagworm, and (2) the ongoing control treatment by trunk chemical injection (TCI) method. The FFB yield fluctuates with the palm age differences (Zabid et al., 2018). Hence, to avoid biases, the selected plantation area had oil palm trees of the same age (six years old and 3–5 meters high). The study area was selected by the purposive random sampling method, comprising palm trees affected by bagworms and treated with TCI (Fig. 1 A-D; Supplementary Fig. 2A). Four plots (four replicates) were established in 4 ha plantations each for TCI, except for the Federal Land Development Authority (FELDA) allocated weaver ant experimental plot of one 4 ha plantation. Three types of plots were established: (i) control plot (not treated by any measures), (ii) plot treated by TCI, and (iii) plot treated by the Asian weaver ant as a biological control agent (BCA). Plots were monitored monthly to record the rate of damage done by bagworms and associate this damage with oil palm productivity/ quality by measuring and recording; (i) foliar injury level, (ii) monthly FFB yield, (iii) oil extraction rate (OER) preluding to fruits grade quality and (iv) the monthly incomes (Ringgit Malaysia RM). The foliar injury level was classified following Exélis & Idris’s study (2013; Exélis, 2014 ). The control plot produced fresh fruit bunches of low quality, rejected by mills processing factories. The palm tree canopies became skeletons (deprived of green leaves) (Fig. 1 A; Supplementary Fig. 2A). 2.1.2. Incipient ant colonies rearing – Colonies expansion set up We have two categories of Asian weaver ant rearing protocols and manipulation. First is r earing naturally by planting citrus tree species, the Calamansi tree ( Citrus microcarpa ) Bunge. (Sapindales: Rutaceae) (Supplementary Fig. 2B) known to attract newly mated mature queens (green colour). In this case, a new colony can reach maturity by 24–36 months of growth (Peng et al., 2012a ; Exélis et al., 2025b). Such colonies can be translocated to bagworms affected oil palm tree canopies to eradicate the infestation. Second is artificially rearing a colony by capturing a mature brood nest to place it at the top middle position of an affected bagworm oil palm tree trunk between the fronds (Supplementary Fig. 2A, red arrow). The translocated brood nest develops into a stable colony within one month, with the appearance of two more nests on average (Exélis et al., 2025b). Weaver ants poorly colonized the study area. Twenty brood nests were collected from the Calamansi orchard inside the oil palm plantation (Supplementary Fig. 2B-C). The orchard serves as a buffer zone promoting the growth and expansion of the weaver ant's incipient colonies (Lim, 2007 ). The collection of brood nests (from mature colonies) was carried out preferably during rainy days, as this corresponds with the emergence of many reproductive individuals (Van Mele & Cuc, 2007; Nielsen et al., 2016 ; Exélis et al., 2025a ). During the lowest activity period of the weaver ant (sunrise), a single nest is cut from the tree (less than 2 meters high) (Peng et al., 2012b ; Exélis et al., 2024 ), sealed tightly fast inside a large, hard fertilizer bag. We manipulated four highly M. plana -affected (level 4) tagged plots of 1 ha each (Supplementary Fig. 3A-B) by posing and fixing the O. smaragdina nests at the median side of the canopy base between the palm fronds for stability (Supplementary Fig. 2A). To avoid direct exposure to strong winds, each nest was placed at the lowest side of the canopy in the center for stability and to preserve nest integrity (corresponding to the top of the palm trunk tip) preferably three meters above the ground to resemble natural nesting site position (Crozier et al., 2010l Exélis et al., 2025b). The nest was directly exposed to the morning light to promote nest building, foraging, and brood rearing. Each brood nest covers an average of 10 palm trees with an average range of 30–85 total nests per colony (Exélis et al., 2023b; Exélis et al., 2025b) by establishing the artificial Line Bridge network to interconnect each canopy to one another (Peng et al., 2004 ). This method facilitates the major workers’ exploration crossover, promoting the colony’s expansion to adjacent palm canopies. Foragers initiated new nest construction within 24 hours (Supplementary Fig. 4A). Such colonies and workers will initiate fast nest construction and establishment (Offenberg, 2015 ). To enhance the possibility of trapping mated queens after rain (Nielsen et al., 2016 ; Nene et al., 2016a ), an artificial nesting network was established with natural palm frond leaflets (Offenberg, 2014 ) (Supplementary Fig. 4B). All bent palm fronds used to construct artificial trap leaflets nests (by binding them together to imitate the weaver ant nest construction technique), never returned to their initial high position. The higher canopy side nest location is significantly more suitable for attracting O. smaragdina queens (Rwegasira et al., 2015 ). The height above the ground defining the nest location in the canopy was fixed at an average of 4 m (Exélis et al., 2025b). Honey and sucrose water (20% concentration), along with chicken intestines (as a protein artificial supplement booster), were provided once a week during one month (Peng et al., 2004 ; Nene et al., 2016b ). To establish a strong Oecophylla colony, one planted host plant (Calamansi, citrus tree) per colony is necessary. To sustain one Asian weaver ant colony occupying an average range of 8–12 oil palm trees, a single favorite host plant (citrus tree) is sufficient (Exélis et al., 2025b). This information helps to know the number of brood nests needed to be translocated to any affected bagworm oil palm plot based on the total number of planted trees for further biological control application. If an area is planted with 100 oil palm trees, deploying 10 brood nests is sufficient protection for the targeted trial area. Since weaver ants are a territorial species, two palm trees were left empty between plots to prevent future fighting between distinct colonies. 2.3. Evaluation of biological control compared to chemical control The trials consisted of three components: control plots without the Asian weaver ant and the TCI, the biological control strategy, and trunk injection chemical treatment. We compared three experimental conditions between (1) O. smaragdina -occupied palm trees, (2) unoccupied palm trees consisting of the control plot critically affected by bagworms, and (3) the TCI treatment using two systemic insecticides, Krotofos 60 (monocrotophos 55% w/w) and multifos 60 (methamidophos 50 w/w), transported to foliage within hours to kill bagworms fast (Salim & Hamid, 2012 ; Salim et al., 2015b ). Plots were monitored monthly to record the rate of damage done by bagworms and associate this damage with oil palm productivity/ quality by measuring and recording; (i) foliar injury level, (ii) monthly FFB yield, (iii) oil extraction rate (OER) preluding to fruits grade quality and (iv) the monthly incomes (Ringgit Malaysia RM). The foliar injury level was classified following Exélis & Idris’s study (2013; Exélis, 2014 ). The control plot produced fresh fruit bunches of low quality, rejected by mills processing factories. The palm tree canopies became skeletons (deprived of green leaves) (Fig. 1 A). 2.4. Bite protection – Repellency – Long-lasting effect (TTO) The study was carried out following the purposive random sampling method. The host plant occupied by weaver ants in Felda Besout, Perak, Malaysia, and Banyuwangi, Indonesia, was selected. The trials were performed on large major workers (experimental unit), known to be more ferocious than smaller workers (Lim, 2007 ; Exélis et al., 2025a ; Exélis et al., 2024 ), to evaluate the impact of pure organic tea tree essence oil extract drops to observe any nausea or escape reaction. The chemical originated from the Thursday Plantation Tea Tree Oil (TTO Australia), 100% pure organic, with a standard bioactive composition, under an act regulated by the ISO standard 4730. Weaver ant aggressive behavior (a 90ᵅ angle gaster elevation, Supplementary Fig. 7) was verified by placing the fingertips on the barrack nest of an occupied Indonesian Bayleaf tree, “Pohon Salam”, Syzygium polyanthum Walp. (Myrtales: Myrtaceae) in Banyuwangi, Indonesia (8°27’19.4” S 114°07’05.7” E) (Supplementary Fig. 6b-c). The nest was disturbed by shaking it to create an emergency response from the colony's major workers. The control test was done directly by human presence without the TTO chemical. A preliminary test was carried out on 3 distinct colonies foraging trails at the base trunk by placing a filter paper disc treated with one pure drop of tea tree oil (TTO). All three replicates reacted positively by avoidance of the filter paper disc (N = 10). As ants quickly showed rejection, a further test was conducted on the human body. One pure drop of TTO was applied to the hair, neck, arms, and legs of the ant-exposed human observer (first author), and was tested to verify its repelling effect on other O. smaragdina colonies. The task involved positioning oneself at a very close distance (an average of 10 cm) from the main tree branches and placing the hands and arms on the weaver ant nests. We recorded the avoidance and biting behavior on an occupied single tree for each colony (N = 10). The effect of the essential oil was evaluated immediately after application to the hands and wrists, then at 15, 30, 45 minutes, and one hour to verify contact persistence during the daily activity peaks corresponding to the hotter periods (1100 to 1530 hours). The experiment was repeated three times (See the two videos of the test from the Mendeley data link https://data.mendeley.com/datasets/y4znm8mgz3/3 , titled disturbed nest and tea tree pure extract repellency test). 2.5. Statistical analysis 2.5.1. BCA versus TCI data The data set was pooled due to its large sample size (2019–2022), which presented a skewed and kurtotic distribution, described as being more suitable (Kim, 2013 ). It was then summarized using descriptive statistics and is considered more accurate to replace the Shapiro-Wilk and Kolmogorov-Smirnov tests for large sample data (Kim, 2013 ). Since the data variable response (income) is right-skewed, did not follow a normal distribution (Limpert et al., 2001 ; Guisan et al., 2002; Coupé, 2018 ; Hastie, 2017), the Generalised Additive Model (GAM), flexible on the normality assumption (Wood, 2017), was applied with the link function identity and follows Exélis et al’s method (2024). The response variable ( Income ) in this study is not normally distributed. Hence, GAM is applied with a gamma distribution using a log link function, which handles skewness naturally and ensures positive predictions (Kim, 2013 ; Coupé, 2018 ). The GAM algorithm is being used for agricultural traits, such as wheat yield, and for solving problems like pest assessment, providing satisfactory insight into predictive events alongside factual ones (Marcillo et al., 2021 ). The income data for five estate groups—TCI OPP I to IV and BC Ants—was analyzed using a second-degree polynomial regression model, incorporating a total of three predictors: Average Yield, OER (Oil Extraction Rate), and Total Yield. The modelling is performed on two predictor variables to obtain three distinct models, taking the incomes as the response factor. In model 1, the income is evaluated with the average yield and total yield metrics. Models 2 and 3 evaluated the combination of average yield and OER, then total yield and OER, respectively. Each model is subjected to an evaluation based on the Degree of Freedom (df), and the Akaike Information Criterion (AIC). To evaluate the adequacy of the GAM model with a Gamma distribution, AIC values are compared — the lower the AIC, the better (Rubec et al., 2016 ). The best model is also selected based on the significance of predictors, using a p-value threshold of 0.05. All the possible models are summarized, and the best among them is chosen based on evaluation metrics of the R-sq (adj), deviance explained, p-values, and AIC values (Table 1 ). X 1 : Average_Yield_permth_ha; x 2 : Total_Yield_ton_perhectar; x 3 : dt $ OER_percent and y : Incomes_RM. This method allowed for capturing non-linear relationships between the variables, average, total yield, and OER with the generated incomes. 240 observations of data were collected each year, totalling 960 records for four years (2019–2022). 2.5.2 Tea Tree Oil evaluation In this analysis, a logistic regression model with a binomial distribution and a logit link function is used to examine the relationship between the Bite variable (Bite = 1, No Bite = 0) as the response, and the Repel variable (Repel = 1, No Repel = 0) as the predictor. The logit link function used is defined as: \(\:logit\left(p\right)=\frac{p}{1-p},\:p\left(\text{0,1}\right)\) . Where log is the natural logarithm (base e), and \(\:\frac{p}{1-p}\) is called the odds of the event, and p is the probability of the event. Both the response and predictor variables are in binary form. Receiver Operating Characteristic (ROC) is a graphical tool used to evaluate the performance of a binary classification model, such as logistic regression. It assesses how well the model distinguishes between two classes (e.g., Bite = Yes/No) and is useful when class distribution is imbalanced. A confusion matrix was performed to compare the observed outcomes to the model’s predicted outcomes. We performed all statistical analyses using R version 4.3.3 (R Core Team, 2024 ). 3. Results 3.1. Oecophylla -bagworms census Ants could neutralize M. plana larvae (N = 30) approaching their protected zone under darkness close to ant nests. The results of the monthly surveys provide this information (Supplementary Tables 1 and 2). The censuses provide information on the level of foliar injury and bagworm density, demonstrating the differences between occupied and unoccupied oil palms observed in the focused study area (Figs. 1 A-F; Supplementary Table 2). It is important to note that only the larval stage is responsible for foliar feeding, causing injury. The red arrows indicate the distribution of brood nests at the top-level positions of several palm tree canopies, ranging from 5 m to 7 m in height (Fig. 1 E-F). Nests exhibit a well-constructed network with a prominent presence of heavy, whitish silk that closes off all exits (highlighted by the black arrow) (Fig. 1 E-F). In contrast, the palm fronds in occupied blocks appear healthy, with little to no observable injuries. 3.2. Experimental results: Trunk chemical injection versus biological control agent The performance of the five plantation groups—BC Ants, TCI OPP I, TCI OPP II, TCI OPP III, and TCI OPP IV—was assessed based on key indicators, including average yield, oil extraction rate (OER), total yield, and income (Supplementary Table 4–2019 to 2022). Biological control ants are the best performers with the highest median of total yield per hectare, with maximum and minimum yields, but still very much higher than the TCI OPP yield. For TCI, TCI OPP IV has the lowest median of yield per hectare. Both TCI OPP I and TCI OPP II have almost the same median of yield per hectare (Fig. 2A-D). Box plots are used to compare the median and variability of the data spread for average yield per month, total yield per hectare (ton), OER percentage, and income across the BCA and TCI groups. In most cases, the BCA group shows the most consistent variability, as the IQR values of the predictors (x 1 , x 2 , x 3 ) are smaller than those of all the TCI groups (Figures A–C). Figure D shows that the median income for the BCA group is significantly higher than that of the TCI groups. We summarize the performance of all groups to expose the overall results, showing a similar trend over four years. BC Ants significantly outperformed all TCI groups. With an average monthly yield of 15.50 t/ha and the highest OER (19.62%), BC Ants achieved the highest total yield (766.17 t) and total income (RM 327,430.76). The average monthly income for BC Ants was RM 27,285.90, more than triple the income of any TCI group. TCI OPP I and II performed moderately well, with yields of 4.89 and 4.56 t/ha/mo, respectively. The OERs were consistent with other TCI groups (~ 17.7%), and their total incomes were RM 99,034.96 and RM 92,401.12. While they lagged significantly behind BC Ants, they maintained a moderate productivity level compared to the lower-performing TCI groups. TCI OPP III and IV displayed the lowest performance across all metrics. Their average yields were below 3.6 t/ha/mo, with monthly incomes under RM 6,000. This trend prevailed for the four years of treatment. The polynomial regression showed a high degree of accuracy in modeling estate income, indicated by an R² score close to 0.99, suggesting that the model explains almost all variability in the income data. The Root Mean Squared Error (RMSE) shows low values across estates, implying minimal deviation between actual and predicted income (Supplementary Fig. 5A-D). BC Ants consistently recorded the highest average yield and total yield, resulting in significantly higher income values compared to TCI groups. TCI’s performance also showed less month-to-month variability. The income data for the four TCI OPP estates (I–IV) and BC Ants estate over the years 2019 to 2022 shows noticeable differences in income levels, growth patterns, and volatility. All four TCI OPP estates demonstrate a generally increasing income trend from 2019 through 2022. However, the increases are modest when compared to BC Ants. BC Ants consistently records income figures far above the TCI OPP estates each year (Supplementary Tables 4 & 5; Figs. 5 A-D). For instance, in 2020 and 2021, its monthly average often exceeded 30,000 while others stayed below 15,000. Despite its higher values, BC Ants displays a stable trend with relatively small variance month to month. The GAM evaluation shows that the income is postively associated with the three predictors, average, total yield and OER (Fig. 3 ). The graph in Fig. 3 shows the fitted income generated from the best model and the actual income. Graphically, it is observed that the actual data is clustered close to the predicted model (straight line). Hence, the fitted income data exhibited close similarity with the actual income data. The model x 1 , x 3 appears as the most fitted with lowest AIC (Table 1 , supplementary Table 5). The minimum income (RM 5064), and max income (RM 94,000), the error is only 9,000l; this is very good results (Supplementary Table 4). The variables x₁ and x₃ are significant predictors (p-value < 0.05) for predicting income. Based on the deviance explained value, 89.1% of the variation in income can be explained by the model that includes only x₁ and x₃, in line with the principle of parsimony. Therefore, the full model, which includes all predictors, is not selected, as it is more complex without providing substantial improvement in model performance. The Generalized Additive Model (GAM) with a Gamma distribution and log link function provides a robust and well-fitting model for predicting income. The selected model includes two significant predictors (x1 and x3), both of which exhibit non-linear relationships with the response, as captured by the smooth terms. Diagnostic assessments, including residual plots, QQ plot of deviance residuals, and the deviance explained value, indicate that the model assumptions are reasonably satisfied. The model explains 89.1% of the deviance and achieves a high adjusted R² of 0.844, suggesting excellent explanatory power. Based on the principle of parsimony and statistical significance, this reduced model is preferred over the full model. Therefore, the fitted GAM is both statistically adequate and practically interpretable for modelling income data with a right-skewed distribution. Table 1 Possible models of Generalised Additive Model with Gamma and log link function. Predictor (s) Significant predictor (P-value < 0.05) DF AIC Adj.R2 Deviance explained x 1 x 1 (0.0000) 8.002 4857.652 0.838 84.4% x 2 x 2 (0.0000) 7.071 4863.224 0.811 83.3% x 3 x 3 (0.0000) 3.430 5090.171 0.556 57.9% x 1 , x 2 x 1 (0.0000); x 2 (0.9150) 9.025 4859.745 0.838 84.4% x 1 , x 3 x 1 (0.0000) ; x 3 (0.0000) 18.904 4789.762* 0.844 89.1% x 2 , x 3 x 2 (0.0000) ; x 3 (0.0000) 18.919 4798.618 0.817 88.7% x 1 , x 2 , x 3 x 1 (0.0000) ; x 2 (0.5910) ; x 3 (0.0000) 19.918 4791.485 0.843 89.2% Note: DF-degrees of freedom, AIC – Akaike’s Information Criterion x 1 : Average_Yield_permth_ha; x 2 : Total_Yield_ton_perhectar; x 3 <- dt$OER_percent y: Incomes_RM (response variable). *The best model 3.4. Bite nuisance protection, repellency, and long-lasting effect: TTO The major workers approached and climbed the hand posed on their nests. Whenever the tea tree essential oil was not used as a protective shield, a plethora of workers came instantly to bite relentlessly. In contrast, no ant bites were recorded during all the repeated tests carried out under tea tree oil spread throughout the hand and arm (N = 90 for three replicates) except for only one incidence (Fig. 4 – Bite over time). Few workers came to attack while the majority stood far from the hand. However, aggressive stances were exhibited by the mandible widely open with the gaster 90°angle elevation marking their territorial characteristic behavior in a swift response to the encroachment (Supplementary Fig. 6a, Fig. 7). The tea tree essential oil demonstrated a powerful repelling effect on the major workers causing avoidance and a rare bites absence behavior (Fig. 4 ). This oil possesses a deterrent odor, having the quality of residual contact persistence for up to one hour upon first application on the body (See the two videos of the test from the Mendeley data link https://data.mendeley.com/datasets/y4znm8mgz3/3 , titled disturbed nest and tea tree pure extract repellency test). The very large negative coefficient value exp (− 21.87) = 3.1 x 10 − 10 is close to zero probability of a bite when repelled. Repel = 1 almost completely prevents bites. However, the huge standard error (7030) and p value = − .998 indicate that this result is not statistically significant. This is likely due to perfect separation and or medium sample size. The area under the curve (AUC) is 0.98, which means the model has a 98% chance of ranking a randomly chosen "positive" case higher than a "negative" one (Fig. 5 ). That is excellent performance. In general, the model accuracy is 96%. The model correctly predicts most "No Bite" cases and does not miss any "Bite" cases. The precision is low (only 1 out of 3 predicted bites was correct). 4. Discussion This study is the first applied research method conducted in a large open-field oil palm plantation to evaluate a biological control agent (BCA). The Asian weaver ant is well-documented for its effectiveness in dealing with diverse pests of economic importance that are harmful to commercial crops (Offenberg, 2015 ). Foliar injury is severe, with 462.30 cm 2 scraped and cut leaves representing 2.794 g of removed biomass by M. plana instar larvae (Tuck et al., 2010 ). The BCA treatment demonstrated the control of the invasive and poly-phytophagous bagworm over 4.5 yearly life cycle generations (average 75 days – Tuck et al, 2010 ; Enting & Latip, 2021 ), corresponding to 18 generations (over 4 years). 4.1. Control method impacts: productivity, quality, and yield-profit 4.1.1 Current method – Management cost (Ringgit Malaysia) The current method of controlling bagworms includes injecting oil palm trunks with systemic organophosphate (which produces lethal effects on pests eating leaves) and aerial spraying of biopesticides (such as Bacillus thuringiensis ). The protocol treatment includes pyrethroids (cypermethrin and deltamethrin) with selective pesticides (lead arsenate) and trichlorfon (Wood & Norman, 2019a ; 2019b ). Cypermethrin and deltamethrin are highly toxic to aquatic animals (Khompun et al., 2024 ), and their environmental persistence seriously threatens humans (Ullah et al., 2018 ). The cost induced by these methods is much higher than the usage of the Asian weaver ant. With an estimated RM 0.70 bagworm TCI cost per palm (Salim et al., 2015b ) and a density of 136–160 oil palm trees per hectare, the average cost is RM 95,000.00 to RM 112,000.00 for a 1000-ha plantation during a severe infestation outbreak. Bacillus thuringiensis (Bt) aerial spraying by drones engages consequent investment that is not affordable by most of the smallholding plantation owners (Masri et al., 2022 ). Sticky traps using female pheromones to lure male individuals into the infested oil palm blocks generated a substantial decline in the male moth population, offered an affordable cost to smallholders (Norman & Othman, 2016 ; Mohd Najib et al., 2017 ; Noorhazwani et al., 2024 ). The information on the benefit-cost of pest control management and the study of pesticide persistence in the agro environment is scarce and limited in open field plantations (Muhamad et al., 2013 ; Sulaiman et al., 2020). The cost-benefit studies comparing Oecophylla BCA to conventional methods are scarce. Peng & Christian ( 2005b ), and Offenberg et al ( 2013 ) are among the rare detailed evaluations with valuable information on this matter. 4.1.2 BCA versus TCI The damages incurred by the bagworm on the unoccupied control plot without the TCI severely affected their FFB grade, resulting in all fruits being rejected and not acceptable for the mill palm oil processing industries. Defined by the OER level, the FFB grade was lower in TCI treatments, while the BCA treatment gave a significantly higher quality for the four years of data record. The significant increase in productivity, quality, and annual yield after the introduction of weaver ants is consistent with other reports from Australia (Peng et al., 2012a ; Forbes & Northfield, 2017 ), the Philippines (Pag-Ong, 2021 ), China and Vietnam (Van Mele & Cuc, 2000 ; Peng et al., 2014 ), Thailand (Offenberg et al., 2013 ), Indonesia (Ridwan et al., 2019 ), and Africa (Van Mele et al., 2007 ). Peak yields tend to occur around March–May and September–November, aligning with bimodal rainfall seasonal patterns in tropical regions (Mumo et al., 2018 ). The biological control of fruit plantations using Oecophylla spp. has been well-documented in Australia and Asia (Krag et al., 2010 ; Peng & Christian, 2006 ; Peng & Christian, 2007 ). A study by Peng & Christian ( 2005b ) demonstrated the higher yield and profit resulting from using Asian weaver ants compared to the relatively limited impact of chemical insecticides in Australian mango orchards. The cost-effectiveness of ant control and significant harvest incomes were also observed in Vietnamese citrus orchards. However, in Thai mango blocks, biological control failed due to fruit-setting destruction by the leafhopper Idioscopus clypealis (Offenberg et al., 2013 ). 4.2. The manipulations and deployment of weaver ant nests in oil palm plantations Based on field experiences, capturing nests is most effective between 2200 hours and 0600 hours (Lim, 2007 ; Exélis et al., 2024 ). During this time, ants are slower, less aggressive, and less likely to launch aggressive attacks on intruders. Spending time under a palm tree with a heavy presence of Oecophylla nests can be challenging (Exélis et al., 2023b; Exélis et al., 2025b). It is possible to swiftly remove a single nest from a short palm tree and relocate it within the same plantation. Careful handling with appropriate disposable materials is necessary when sampling brood nests that contain a high abundance of ant individuals across all castes. Introducing the captured nest on a new palm tree affected by bagworm defoliators, along with chicken, has proven effective. Transferring nests over long distances for biological control trials is not recommended. The newly introduced biological control agent could act similarly to an exotic species. Risks to human, animal, and plant health and potential environmental damages have been reported (De Clercq et al., 2011 ). Reduction of other natural native enemies is reported in multiple cases in both tropical and temperate climate countries (Van Lenteren et al., 2006 ). 4.3 Bite protection – Repellency – Long lasting effect (TTO) An alternative approach to mitigate ant attacks is to employ natural insect repellents. Melaleuca alternifolia tea tree is a novelty, and few studies have reported similar breakthroughs from the application of oils to repel O. longinoda in Senegal (Chailleux et al., 2019 ). The essence oil's bioactive compounds (i.e., terpenes and tertiary alcohols) provide a strong defensive function to the plants, resulting in expelling insect intruders or causing mortality (Buteler et al., 2021 ). Generally, essential oils are vulnerable to demonstrating low persistence in the environment due to fast volatilization and oxidative degradation from heat and light (El et al., 2015). The Asian weaver ant's foraging activity disruption, causing instant bite nuisance nullity, is a breakthrough finding. TTO application on hands, neck, and head provided full protection from ant bite nuisance, repelled ferocious major workers with a long lasting effect (one hour). Venturing into territories dominated by O. smaragdina consistently resulted in ant bites and immediate aggression. Ecological damage incurred to the environment by synthetic pesticides is well documented, and the application of BCA throw selective natural enemies for augmentative biological control is becoming more widespread worldwide (Van Lenteren et al., 2018 ). The efforts to reduce reliance on manual human harvesters are timely (Radzi et al., 2023 ), hence minimizing ant bites. 5. Conclusion The study discovered that maintaining a sufficient numerical ratio between weaver ant predator-defoliators and foragers, favoring the latter, facilitates the effective suppression of invasive bagworms. The healthy green foliage in occupied palms contrasted strongly with the skeletal sight of unoccupied canopies. The FFB productivity and quality improve with higher monthly incomes. The innovation of M. alternifolia tea tree essential oil as an aggressively effective weaver ant repellent vector opens new alternatives. The future adoption of the Asian weaver ant for better, and environmentally friendly, and cheaper cost pest management in the tropical agro-systems of Asia. Consequently, the study concludes that adopting Asian weaver ant colonies is a feasible and productive strategy that offers smallholders in the oil palm industry an affordable and effective means of controlling the invasive bagworm Metisa plana . Declarations DECLARATION OF COMPETING INTEREST The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. SUPPLEMENTARY INFORMATION The supporting information is provided in this manuscript. FUNDING DECLARATION This study did not receive funding for support. Author Contribution Exélis Moïse Pierre: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Prepared tables/figures, Project administration, Resources, Validation, Visualization, Writing – Original Draft, Writing – Review & Editing. Rosli Ramli: Project administration, Resources, Supervision, Writing – Review & Editing. Roslinazairimah Zakaria: Formal analysis, Methodology, Software, Visualization, Writing – Review & Editing. Azarae Hj Idris: Investigation, Project administration, Resources, Supervision, Writing – Original Draft. Rabha W. Ibrahim: Formal analysis, Methodology, Software, Visualization, Writing – Review & Editing. Acknowledgement This study is a part of the first author’s PhD dissertation supported under a French-European Union complete scholarship grant through the local government authority of “Collectivité Territoriale de la Martinique-CTM” in the Meso-American Caribbean (awarded to EMP). Special thanks to the Malaysian Palm Oil Board (MPOB), Federal Land Development Authority FELDA Malaysia, Universiti Malaya Oil Palm Research Center Sdn. Bhd for granting access permission to its facilities and plantations in Malaysia. We are grateful for the helpful reviews performed by Dr. Eric Wajnberg, Editor in Chief of BioControl Journal, and Dr. Francis P. F. Reay-Jones, Receiving Editor of Crop Protection Journal. Special thanks to the management of “Surau An-Nur, section 20 Shah Alam Selangor State, Malaysia” for providing accommodation and daily services, helping to sustain the needs during the writing and correction period of the manuscript. EMP received a doctoral scholarship from the local government authority of the Martinique Island “Collectivité Territoriale de la Martinique-CTM.”, under a French-European Union scheme, financial support (overseas travel, accommodation, daily life cost – not project funding) for students originating from the Caribbean Islands. Data Availability The data presented in this study are openly available in this manuscript and can be retrieved in the below link (Raw dataset BCA vs TCI and videos disturbed nest – tea tree pure extract repellence positive test): https://data.mendeley.com/datasets/y4znm8mgz3/3 References Adhawiyah, N. R., Noorhazwani, K., Bakeri, S. A., Zainuddin, N., Keni, M. F., & Masri,M. M. M. (2023). Impact of environmental factors on the larval population of bagworm, Metisa plana Walker (Lepidoptera: Psychidae) in oil palm smallholdings. Serangga, 28(2): 149–161. Basri, A.H. H., Girsang, S. A. & Novita, A.(2022). The Impact of bagworm ( Metisa plana ) attacks on oil palm ( Elaeis guineensis Jacq.) production at Tanjung Beringin Plantation, PT. Langkat Nusantara Kepong, Indonesia. International Journal of Biosciences and Biotechnology 10(1): 1–12. Bedini, S., Cosci, F., Tani, C., Pierattini, E. C., Venturi, F., Lucchi, A., & Ioriatti, C et al. (2020). "Essential oils as post-harvest crop protectants against the fruit fly Drosophila suzukii : Bioactivity and organoleptic profile." Insects, 11, no. 8: 508. Buteler, M., Alma, A. M., Herrera, M. L., Gorosito, N. B., & Fernández, P. C. (2021). Novel organic repellent for leaf-cutting ants: tea tree oil and its potential use as a management tool. International Journal of Pest Management , 67 (1), 1–9. Chailleux, A., Stirnemann, A., Leyes, J., & Deletre, E. (2019). "Manipulating natural enemy behavior to improve biological control: attractants and repellents of a weaver ant." Entomologia Generalis, 38: 191–210.. Che Hussian, C. H. A., Seman-Kamarulzaman, A. F., Othman, N. W., Nor Muhammad, N. A., Jalinas, J., Zainal Abidin, C. M. R., … Hassan, M. (2025). Global research trends in oil palm pests and their potential threat: a bibliometric analysis. International Journal of Pest Management , 1–22. Coupé, C. (2018). Modeling linguistic variables with regression models: Addressing non-Gaussian distributions, non-independent observations, and non-linear predictors with random effects and generalized additive models for location, scale, and shape. Frontiers in psychology , 9 , 513. De Clercq, P., Mason, P. G., & Babendreier, D. (2011). Benefits and risks of exotic biological control agents. BioControl, 56 , 681–698. El Asbahani, A., Miladi, K., Badri, W., Sala, M., Addi, E. A., Casabianca, H., … Elaissari, A. (2015). Essential oils: From extraction to encapsulation. International journal of pharmaceutics, 483 (1–2), 220–243. Enting, C. E., & Latip, S. N. H. M. (2021). Life cycle of oil palm bagworm, Metisa plana Walker (Lepidoptera: Psychidae) at different temperatures under controlled environment. Serangga 2021, 26(2): 151–165. Exélis, M. P. (2014). An ecological study of Pteroma pendula (Lepidoptera: Psychidae) in oil palm plantations with emphasis on the predatory activities of Oecophylla smaragdina (Hymenoptera: Formicidae) on the bagworm. Master Dissertation, Universiti Malaya, Kuala Lumpur, Malaysia. Exélis, M. P., & Idris, A. H. (2013). Studies on the predatory activities of Oecophylla smaragdina (Hymenoptera: Formicidae) on Pteroma pendula (Lepidoptera: Psychidae) in oil palm plantations in Teluk Intan, Perak (Malaysia). Asian Myrmecology, 5, 163–176. Exélis M. P., Ramli, R., Idris, A. H., & Sani, M. S. A. (2022). Estimation of worker population size-density by nest counting in the Asian weaver ant, Oecophylla smaragdina (Formicidae: Formicinae) and its dynamic in oil palm plantations industry. 2022, preprint-researchsquare. https://doi.org/10.21203/rs.3.rs-2321637/v1 Exélis, M.P.; Ramli, R.; Ibrahim, R.W.; Idris, A.H. (2023a). Foraging Behaviour and Population Dynamics of Asian Weaver Ants: Assessing Its Potential as Biological Control Agent of the Invasive Bagworms Metisa plana (Lepidoptera: Psychidae) in Oil Palm Plantations. Sustainability, 15, 780. https://doi.org/10.3390/su15010780 Exélis. M. P., Ramli, R., Idris, A. H., Ibrahim, W. R., & Clemente-Orta, M. G. (2023b). Distribution and Nest Occupancy Patterns of Oecophylla smaragdina (Hymenoptera: Formicidae) Colonies in Southeast Asia Oil Palm Plantations. Preprints.org, 2023040057. https://doi.org/10.20944/preprints202304.0057.v1 Exélis, M. P., Ramli, R., Hj Idris, A., Zakaria, R., Yacob, Z., Ibrahim, R. W., Yaakop, S., & Othman, N. W. (2023c). The Social Organisation of Oecophylla smaragdina (Hymenoptera: Formicidae) Colonies and Their Functional Activity. Preprints, 2023040067. https://doi.org/10.20944/preprints202304.0067.v1 Exélis, M. P., Ramli, R., Latif, S. A. A., Idris, A. H., Clemente-Orta, G., & Kermorvant, C. (2024). Elucidating the daily foraging activity pattern of Oecophylla smaragdina to minimize bite nuisances in Asia large agro-system plantations. Heliyon , 10 (4). Exélis, M. P., Ramli, R., Azarae, H. I., Roslinazairimah, Z., Zubaidah, Y., Rabha, W. I., Salmah, Y., & Nurul Wahida, O. (2025a). The social organization of the Asian weaver ant colonies: A natural enemy novel sub-castes worker’s functional activity findings. In Press, PlosOne. DOI: 10.1371/journal.pone.0326030 Exélis. M. P., Ramli, R., Idris, A. H., Ibrahim, W. R., & Clemente-Orta, M. G. (2025b). Distribution and Nest Occupancy Patterns of Oecophylla smaragdina (Hymenoptera: Formicidae) Colonies in Southeast Asia Oil Palm Plantations. Asia-Pacific Entomology Journal . Accepted for publication (not in Press yet). https://doi.org/10.20944/preprints202304.0057.v1 Forbes, S. J., & Northfield, T. D. (2017). " Oecophylla smaragdina ants provide pest control in Australian cacao." Biotropica, 49(3), 328–336. Kalidas, P. (2012). Pest problems of oil palm and management strategies for sustainability. Agrotechnology, S11 , 1 . Kamarudin, N., Ali, S. R. A., Masri, M. M. M., Ahmad, M. N., & Manan, C. A. H. C. (2017). Controlling Metisa plana Walker (Lepidoptera: Psychidae) outbreak using Bacillus thuringiensis at an oil palm plantation in Slim River, Perak, Malaysia. Journal Oil Palm Research, 29 (1), 47–54. Khompun, W., Chonlada, D., T., & Waraporn, C. (2024). "Accumulation and Phytotoxicity of Cypermethrin and Deltamethrin to Aquatic Plants." Pertanika Journal of Tropical Agricultural Science , 47(1). Kim, H. Y. (2013). Statistical notes for clinical researchers: assessing normal distribution (2) using skewness and kurtosis. Restorative dentistry & endodontics , 38 (1), 52. Krag, K., Lundegaard, R., Offenberg, J., Nielsen, M.G., & Wiwatwittaya, D. (2010). "Intercolony transplantation of Oecophylla smaragdina (Hymenoptera: Formicidae) larvae." Journal of Asia-Pacific Entomology, 13, (2), 97–100. Lim, G.T. (2007). Enhancing the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), for biological control of a shoot borer, Hypsipyla robusta (Lepidoptera: Pyralidae), in Malaysian mahogany plantations. Doctoral Dissertation, Virginia Tech University, USA. https://vtechworks.lib.vt.edu/handle/10919/26850 Limpert, E., Stahel, W. A., & Abbt, M. (2001). Log-normal distributions across the sciences: keys and clues: on the charms of statistics, and how mechanical models resembling gambling machines offer a link to a handy way to characterize log-normal distributions, which can provide deeper insight into variability and probability—normal or log-normal: that is the question. BioScience , 51 (5), 341–352. Marcillo, G. S., Martin, N. F., Diers, B. W., Da Fonseca Santos, M., Leles, E. P., Chigeza, G., & Francischini, J. H. (2021). Implementation of a generalized additive model (Gam) for soybean maturity prediction in african environments. Agronomy , 11 (6), 1043. Masri, M. M. M., Kamarudin, N., Napiah, N. R. M. A., & Keni, M. F. (2022). Effectiveness of Bacillus thuringiensis aerial spraying against the bagworm, Metisa plana Walker (Lepidoptera: Psychidae) outbreak in oil palm using drone. Journal of Oil Palm Research, 34(2), 276–288. Mohd Najib, A., Kamarudin, N., Ahmad, S. N., Arshad, O., Masri, M. M. M., Moslim, R., & Kushairi, A. (2017). Efficacy of pheromone trapping and aerial spraying of Bacillus thuringiensis (Bt) for controlling bagworm, Metisa plana Walker (Lepidoptera: Psychidae) in Yong Peng, Johor, Malaysia. Journal of Oil Palm Research, 29 (1), 55–65. Muhamad, H., Ramli, M. I., Zakaria., & Sahid, I. (2013). The fate of diuron in soil in a Malaysian oil palm plantation. Journal of Oil Palm Research, 25 (1), 149–158. Mumo, L., Yu, J., & Fang, K. (2018). Assessing impacts of seasonal climate variability on maize yield in Kenya. International Journal of Plant Production , 12 (4), 297–307. Nene, W. A., Rwegasira, G. M., Nielsen, M. G.; Mwatawala, M., & Offenberg, J. (2016a). Nuptial flights behavior of the African weaver ant, Oecophylla longinoda Latreille (Hymenoptera: Formicidae) and weather factors triggering flights. Insectes sociaux, 63(2), 243–248. Nene, W., Rwegasira, G. M., Mwatawala, M., Nielsen, M. G., & Offenberg, J. (2016b). Foraging behavior and Preferences for Alternative Supplementary Feeds by the African Weaver Ant, Oecophylla longinoda Latreille (Hymenoptera, Formicidae). Journal of Hymenoptera Research, 50, 117–128. Nielsen, M. G., Peng, R., Offenberg, J., & Birkmose, D. (2016). Mating strategy of Oecophylla smaragdina (Hymenoptera: Formicidae) in northern Australia. Austral Entomology, 55(3), 261–267. Noorhazwani K,, Siti Nurulhidayah A, Mohd Najib A, Mohd Fahmi, K., Nur Robaatul Adhawiyah, M. A. N., Shamsilawani, A. B., Mohamad, R. S & Mohamed, M. M. (2024). Quad Trap: An Alternative Approach to increase trapping efficiency of the male bagworm, Metisa plana Walker. Special issue: 5th INTERNATIONAL SYMPOSIUM ON INSECTS (ISOI2023), “UNVEILING THE HIDDEN PROSPECT OF INSECTS”, 11–13 SEPTEMBER 2023. Serangga, 29(2): 177–188. Norman, K., & Othman, A. (2016). Diversity and activity of insect natural enemies of the bagworm (Lepidoptera: Psychidae) within an oil palm plantation in Perak, Malaysia. Journal of oil Palm research , 28 (3), 296–307. Offenberg, J. (2014). The use of artificial nests by weaver ants: A preliminary field observation. Asian Myrmecology, 6(1), 6. Offenberg, J. (2015). "Ants as tools in sustainable agriculture." Journal of Applied Ecology, 52, no. 5: 1197–1205. Offenberg, J., Cuc, N. T. T., & Wiwatwitaya, D. (2013). The effectiveness of weaver ant ( Oecophylla smaragdina ) biocontrol in Southeast Asian citrus and mango. Asian Myrmecology, 5, 139–149. Pag-Ong, Anthony Ian. (2021). "Taxonomy and diversity of ants associated with cacao and evaluation of Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae) for biological control of Helopeltis bakeri Poppius (Hemiptera: Miridae) in Quezon and Laguna, Philippines." Doctorate dissertation, De La Salle University, Manila Philippines. Peng, R. K., & Christian, K. (2005a). Integrated pest management in mango orchards in the Northern Territory Australia, using the weaver ant, Oecophylla smaragdina,(Hymenoptera: Formicidae) as a key element. International Journal of Pest Management , 51 (2), 149–155. Peng, R. K., & Christian, K. (2005b). The control efficacy of the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), on the mango leafhopper, Idioscopus nitidulus (Hemiptera: Cicadellidea) in mango orchards in the Northern Territory. International Journal of Pest Management, 51(4), 297–304. Peng, R. K., & Christian, K. (2006). Effective control of Jarvis’s fruit fly, Bactrocera jarvisi (Diptera: Tephritidae), by the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), in mango orchards in the Northern Territory of Australia. International Journal of Pest Management, 52(4), 275–282. Peng, R. K., & Christian, K. (2007). The effect of the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), on the mango seed weevil, Sternochetus mangiferae (Coleoptera: Curculionidae), in mango orchards in the Northern Territory of Australia. International Journal of Pest Management, 53(1), 15–24. Peng, R. K., Christian, K., & Gibb, K. (2004). "Implementing Ant Technology in Commercial Cashew Plantations and Continuation of Transplanted Green Ant Colony Monitoring: A Report for the Rural Industries Research and Development Corporation, Australian government." RIRDC Publication No W04/088. Peng, R., Christian, K., & Reilly, D. (2012a). Biological control of the fruit-spotting bug Amblypelta lutescens using weaver ants Oecophylla smaragdina on African mahoganies in Australia. Agricultural and Forest Entomology, 14(4) 428–433. Peng, R., Christian, K., & Gibb, K. (2012b). The best time of day to monitor and manipulate weaver ant colonies in biological control. Journal of Applied Entomology, 136 (1-2), 155–160. Peng, R., Lan, L.P., & Christian, K. (2014). Weaver Ant Role in Cashew Orchards in Vietnam. Journal of Economic Entomology, 107(4), 1330–1338. Radzi, M. K. F. M., Khalid, M. R. M., Azaman, M. I. H., Mohamed, A., Thadeus, D. J., & Bakri, M. A. M. (2023). The Initiative to Further Enhance Technology Adoption in the Malaysian Oil Palm Industry. Advances in Agricultural and Food Research Journal , 4 (2). R Core Team. (2024). R: A language and environment for statistical computing (Version 4.3.3) [Software]. R Foundation for Statistical Computing. https://www.R-project.org/ Ridwan, A., Nurariaty A., & Tamrin, A. M. (2019). "Exposure Test of Oecophylla smaragdina (Hymenoptera: Formicidae) for Controlling Damage from Prays Endocarpa (Lepidoptera: Yponomeutidae) on Pummelo ( Citrus Maxima Merr.)." International Journal of Scientific Research in Science and Technology, 6(6), 289–295. https://doi.org/10.32628/IJSRST196663 Rubec, P. J., Kiltie, R., Leone, E., Flamm, R. O., McEachron, L., & Santi, C. (2016). Using delta-generalized additive models to predict spatial distributions and population abundance of juvenile pink shrimp in Tampa Bay, Florida. Marine and coastal fisheries , 8 (1), 232–243. Rwegasira, R. G., Maulid, M., Rwegasira, G. M., Nielsen G. M, & Offenberg, J. (2015). "Comparing different methods for trapping mated queens of weaver ants ( Oecophylla longinoda ; Hymenoptera: Formicidae)." Biocontrol Science and Technology, 25(5), 503–512. Salim, H., & Hamid, N. H. (2012). Evaluation of several chemical control approaches against bagworm, Metisa plana Walker (Lepidoptera: Psychidae) in Felda oil palm plantations. Plant, 88, 785–799. Salim, H., Rawi, C. S. M., Hamid, N. H., Ismail, S. T., Abidin, C. M. R. Z., & Ahmad, A. H. (2015b). Efficacy of trunk injection technique of systemic insecticide against bagworms on oil palm. Advances in Environmental Biology, 9(27), 129. Sulaiman, S. S. (2020). Regulating good agriculture practices (Gaps) in enhancing sustainability of halal food: Malaysian experience. Malaysian Journal of Consumer and Family Economics , 24 (2), 32–45. Syarif, M.N.Y., Asib, N., Ahmad, S.N., Bakeri, S.A. & Mazmira, M.M.M. 2023. Identification of Cordyceps javanica and its effectiveness in controlling bagworm, Pteroma pendula Joannis (Lepidoptera: Psychidae). Serangga 28(2): 14–27. Ting, A., Abidin, C. M, Hamid, N. H., Azzam, G., & Salim, H. (2023). Uncovering the Microbiota of Bagworm Metisa plana (Lepidoptera: Psychidae) in Oil Palm Plantations in Malaysia. Tropical Life Sciences Research, 34(1):185. Tuck, H. C., Ibrahim, Y., & Chong, K. K. (2010). Comparative life histories, demographic statistics and damage potential of the bagworms Pteroma pendula and Metisa plana in oil palm. Journal of Science and Mathematics Letters, 2 (2), 39–53. Ullah, S., Zuberi, A., Alagawany, M., Farag, M. R., Dadar, M., Karthik, K., … Iqbal, H. M. (2018). Cypermethrin induced toxicities in fish and adverse health outcomes: Its prevention and control measure adaptation. Journal of Environmental Management, 206 , 863–871. Van Lenteren, J. C., Bale, J., Bigler, F., Hokkanen, H. M. T., & Loomans, A. J. M. (2006). Assessing risks of releasing exotic biological control agents of arthropod pests. Annual review of entomology, 51 (1), 609–634. Van Lenteren, J. C., Bolckmans, K., Köhl, J., Ravensberg, W. J., & Urbaneja, A. (2018). Biological control using invertebrates and microorganisms: plenty of new opportunities. BioControl, 63 , 39–59. Van Mele, P. (2008). A historical review of research on the weaver ant Oecophylla in biological control. Agricultural and Forest Entomology, 10, 13–22. Van Mele, P., & Cuc, N. T. T. (2000). Evolution and status of Oecophylla smaragdina (Fabricius) as a pest control agent in citrus in the Mekong Delta, Vietnam. International Journal of Pest Management, 46, 295–301. Van Mele, P. & Cuc, N. T. T. (2007). Ants as Friends: Improving your Tree Crops with Weaver Ants (2nd Edition). Africa Rice Center (WARDA), Cotonou, Benin, and CABI, Egham, UK. 72 pp. Van Mele, P., Nguyen, T. T. C.; Seguni, Z., Camara, K., & Offenberg, J. (2009). Multiple sources of local knowledge: a global review of ways to reduce nuisance from the beneficial weaver ant Oecophylla . International Journal of Agricultural Resources Governance and Ecology, 8, 484–504. Way, M. J., & Khoo, K. C. (1992). Role of ants in pest management. Annual Review of Entomology, 37, 479–503. Wood, B. J., & Norman, K. (2019a). "A review of developments in integrated pest management (IPM) of bagworm (Lepidoptera: Psychidae) infestation in oil palms in Malaysia." Journal of Oil Palm Research, 31(4), 529–539. Wood, B. J & Norman, K. (2019b). "Bagworm (Lepidoptera: Psychidae) Infestation in the centennial of the Malaysian oil palm industry—A review of causes and control." Journal of Oil Palm Research 31(3), 364–380. Additional Declarations No competing interests reported. Supplementary Files SupplementaryEMPBCATCI120725.docx 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-7215952","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":493922274,"identity":"cf527614-ee39-44fe-b30f-b0678d674094","order_by":0,"name":"Moïse Pierre Exélis","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+UlEQVRIie2QsQrCMBCGEw7qonatk69QcBV8EJcWwS0uLh1UOsUl7gqir6BL50ghXQo+gIsuzrp1qOC1KLrUOgrmg/zccB+XO0I0mt+ESgfTyGsPH4Bf6rwpcabQL5TXQJ7nZ8W0elIeUzKoV2bny3U17ppTVBIvKFQaQjnS5WRoVKPWYhFEbB5Sn4r4UKjYkbCl6xOXW32AWqCYjwpQXqx0QvMinRSV5hngtlRsXabYFYEXM7IpBuCtRmxTplixwo9xC3fpAxVKsi0qu0+7mPPe6ZSk7UFzqoAkowlb7cPdMfGKlecw51GEecqy/oynMvmmWaPRaP6MOydQWsbdLu0oAAAAAElFTkSuQmCC","orcid":"","institution":"Universiti Malaya","correspondingAuthor":true,"prefix":"","firstName":"Moïse","middleName":"Pierre","lastName":"Exélis","suffix":""},{"id":493922275,"identity":"5ab84cfc-7434-49fd-8d0e-29457a5397d7","order_by":1,"name":"Ramli Rosli","email":"","orcid":"","institution":"Universiti Malaya","correspondingAuthor":false,"prefix":"","firstName":"Ramli","middleName":"","lastName":"Rosli","suffix":""},{"id":493922276,"identity":"c64d4b05-b890-4b9a-8785-38dcb6abf40e","order_by":2,"name":"Roslinazairimah Zakaria","email":"","orcid":"","institution":"Universiti Malaya","correspondingAuthor":false,"prefix":"","firstName":"Roslinazairimah","middleName":"","lastName":"Zakaria","suffix":""},{"id":493922277,"identity":"54594b2d-e3e4-45a8-8d18-2a08872036cc","order_by":3,"name":"Azarae Hj Idris","email":"","orcid":"","institution":"Universiti Malaya","correspondingAuthor":false,"prefix":"","firstName":"Azarae","middleName":"Hj","lastName":"Idris","suffix":""},{"id":493922278,"identity":"9bf8eb5f-bb85-48b9-885f-c32bbe7f8038","order_by":4,"name":"Rabha W. Ibrahim","email":"","orcid":"","institution":"Al- Ayen University","correspondingAuthor":false,"prefix":"","firstName":"Rabha","middleName":"W.","lastName":"Ibrahim","suffix":""}],"badges":[],"createdAt":"2025-07-25 16:08:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7215952/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7215952/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88324196,"identity":"db417fc8-cd23-44ea-9317-fde0605e1e27","added_by":"auto","created_at":"2025-08-05 09:25:27","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":98773,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA-F.\u003c/strong\u003e \u003cem\u003eM. plana\u003c/em\u003eoutbreak in Felda Besout, Perak. A- Foliar injury of level 4. B- Level 3. C. Level 2 and D- Level 1 with characteristic hook type \u003cem\u003eM. plana\u003c/em\u003e pupae (red circle) at the adaxial side of the leaflet frond. E- \u003cem\u003eO. smaragdina\u003c/em\u003e brood nests. F- The red arrows indicate the freshly constructed brood nests and the heavy presence of silk-whitish (black arrow).\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/563adb59d90577f0f32e8fbc.jpg"},{"id":88324200,"identity":"6e9782a1-0fb3-441a-b7f0-f680aa3f3890","added_by":"auto","created_at":"2025-08-05 09:25:27","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":70630,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA-D.\u003c/strong\u003e Graphics summary of the median performance in average yield (A), total yield (B), OER (C), and income (D).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/d35b0aeb62104b3cfb54b18b.png"},{"id":88324208,"identity":"652da298-f9ab-4e44-a765-e7fb855375bd","added_by":"auto","created_at":"2025-08-05 09:25:27","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":31763,"visible":true,"origin":"","legend":"\u003cp\u003eGraphs of the models generated by the generalized additive model (GAM).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/357308607f146c483bcbae9f.png"},{"id":88324522,"identity":"d24aa9f4-81a9-41f1-9c62-34a170aa698d","added_by":"auto","created_at":"2025-08-05 09:33:27","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":33688,"visible":true,"origin":"","legend":"\u003cp\u003eTea tree essential oil repellency, bite nuisance protection test\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/2f11c8f65bc0cc7c9d6f8853.png"},{"id":88324204,"identity":"1a68f432-146b-4a27-a3f3-a28ac7109c62","added_by":"auto","created_at":"2025-08-05 09:25:27","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":13923,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver Operating Characteristic graphic.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/e6144dd207c65d77cdde9fb4.png"},{"id":90536099,"identity":"b8e931f9-2bb0-40c5-b0de-9b1c5df04795","added_by":"auto","created_at":"2025-09-03 20:16:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1218698,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/73988481-abbf-4e4d-8839-467b7b35372a.pdf"},{"id":88324219,"identity":"3ebb72ee-1c07-4327-81bb-fc58439fb6c9","added_by":"auto","created_at":"2025-08-05 09:25:28","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":6497272,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryEMPBCATCI120725.docx","url":"https://assets-eu.researchsquare.com/files/rs-7215952/v1/13e2791370435b1cb7eb71c4.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003e\u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae): A Biological Control Agent of the Invasive Bagworms \u003cem\u003eMetisa plana\u003c/em\u003e (Lepidoptera: Psychidae)\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003ePlaying a significant role as indigenous leaf-eating pests of the African oil palms (\u003cem\u003eElaeis guineensis\u003c/em\u003e) Jacq. (Arecales: Arecaceae), in Malaysia and Indonesia (Kamarudin et al., 1994), the bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker, is identified as the most dominant destructive pest species (Ting et al., \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Syarif et al., \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The defoliation induces a decrease in photosynthesis rate, hence lowering monthly and yearly yield production (Enting \u0026amp; Latip, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), reaching a fresh fruit bunches (FFB) average loss of 10 tons per acre (Kalidas, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Moderate defoliation (10\u0026ndash;13%) by bagworms can result in a 30\u0026ndash;40% decrease in yield (Mohd Johari \u003cem\u003eet al\u003c/em\u003e., 2023), but more severe infestations can cause up to 43% yield loss (Adhawiyah et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Basri et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The economic losses exceeded USD 25\u0026nbsp;million yearly (Che Hussian et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Thus, the damage caused by the invasive \u003cem\u003eM. plana\u003c/em\u003e species is likely to become more widespread without proper control measures (Wood \u0026amp; Norman, \u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e2019a\u003c/span\u003e; Wood \u0026amp; Norman, \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e2019b\u003c/span\u003e). In 2013, bagworms were officially classified as quarantine pests in Malaysia (Kamarudin et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). To eliminate this pest, broad-spectrum, long-lasting contact pesticides (Cypermethrin and deltamethrin are highly toxic) have been used (Wood \u0026amp; Norman, \u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e2019a\u003c/span\u003e). This led to an ecological disaster, marked by the indiscriminate suppression of beneficial insects and the accumulation of chemical hazards in agricultural soils and the environment, contributing to the development of pesticide resistance among target species (Wood \u0026amp; Norman, \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e2019b\u003c/span\u003e). An alternative, cheap, and environmentally friendly method of control is necessary. The Asian weaver ant (\u003cem\u003eOecophylla smaragdina\u003c/em\u003e F.) has controlled over 50 pest species across 12 diverse crops (Way \u0026amp; Khoo, \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e1992\u003c/span\u003e; Peng et al., \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2012a\u003c/span\u003e). Its effectiveness as a biological control agent has been compared with pesticides in Southeast Asia and Australia (Van Mele \u0026amp; Cuc, \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Peng \u0026amp; Christian, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2005a\u003c/span\u003e). Bagworm infestations are critical in unoccupied weaver ant palms (Ex\u0026eacute;lis \u0026amp; Idris, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). In unoccupied plantations, collected brood nests are translocated to rear incipient colonies in the outbreak-affected plants (Offenberg et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Introducing new nests to boost incipient colonies in affected areas is a documented effective method (Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e, b). The ants' major workers engage in daily predation through extensive foraging and territorial behaviour (Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2024\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2025a\u003c/span\u003e). Their bites, resulting in the rejection of using Asian weaver ants as a biological control agent (BCA) in some cases (Van Mele, \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2008\u003c/span\u003e; Van Mele et al., \u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Offenberg, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Some plantation workers even resorted to burning ants\u0026rsquo; nests or exterminating them with poisons (Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e). Therefore, we propose and hypothesize that the tea tree (\u003cem\u003eMelaleuca linariifolia\u003c/em\u003e var. \u003cem\u003ealternifolia\u003c/em\u003e (Maiden \u0026amp; Betche) essential oil is a potential repellent of weaver ants (Chailleux et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Assuming an output shows a high R\u0026sup2; (variance proportion) and relatively low Root Mean Squared Error (RMSE), we hypothesized that the combination of Average Yield, Oil Extraction Rate (OER), and Total Yield can successfully predict income with some nonlinear adjustments using a polynomial regression. This study assesses (1) the ability of weaver ants to control bagworm populations by comparison with the trunk chemical injection (TCI) method. The efficiency levels were measured based on various productivity parameters, i.e., foliar injury level, monthly fresh fruit bunches (FFB) yield, and OER relating to grade quality. In addition, we assess (2) the effectiveness of the tea tree oil (TTO) essential oil as a treatment for (i) bite protection, (ii) repelling the Asian weaver ant, and (iii) determining their long-lasting effect.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1. Study sites and plot selection\u003c/h2\u003e\u003cp\u003eThis study was conducted in oil palm plantations located in Felda Gunung Besout, Perak, Malaysia, from 2019\u0026ndash;2022 (N03\u0026deg;49.408\u0026rsquo; E101\u0026deg;19.775\u0026rsquo; and 3\u0026deg;50\u0026rsquo;30\u0026rdquo; 101\u0026deg;18\u0026rsquo;08\u0026rdquo; E; Supplementary Fig.\u0026nbsp;1). The total plantation's area is 1064.53 ha, and it was further divided into 4-ha plots allocated to 266 smallholders. The oil palm plots were selected based on: (1) the presence of bagworm, and (2) the ongoing control treatment by trunk chemical injection (TCI) method. The FFB yield fluctuates with the palm age differences (Zabid et al., 2018). Hence, to avoid biases, the selected plantation area had oil palm trees of the same age (six years old and 3\u0026ndash;5 meters high). The study area was selected by the purposive random sampling method, comprising palm trees affected by bagworms and treated with TCI (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA-D; Supplementary Fig.\u0026nbsp;2A). Four plots (four replicates) were established in 4 ha plantations each for TCI, except for the Federal Land Development Authority (FELDA) allocated weaver ant experimental plot of one 4 ha plantation. Three types of plots were established: (i) control plot (not treated by any measures), (ii) plot treated by TCI, and (iii) plot treated by the Asian weaver ant as a biological control agent (BCA). Plots were monitored monthly to record the rate of damage done by bagworms and associate this damage with oil palm productivity/ quality by measuring and recording; (i) foliar injury level, (ii) monthly FFB yield, (iii) oil extraction rate (OER) preluding to fruits grade quality and (iv) the monthly incomes (Ringgit Malaysia RM). The foliar injury level was classified following Ex\u0026eacute;lis \u0026amp; Idris\u0026rsquo;s study (2013; Ex\u0026eacute;lis, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). The control plot produced fresh fruit bunches of low quality, rejected by mills processing factories. The palm tree canopies became skeletons (deprived of green leaves) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA; Supplementary Fig.\u0026nbsp;2A).\u003c/p\u003e\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\u003ch2\u003e2.1.2. Incipient ant colonies rearing \u0026ndash; Colonies expansion set up\u003c/h2\u003e\u003cp\u003eWe have two categories of Asian weaver ant rearing protocols and manipulation. First is \u003cb\u003er\u003c/b\u003eearing naturally by planting citrus tree species, the Calamansi tree (\u003cem\u003eCitrus microcarpa\u003c/em\u003e) Bunge. (Sapindales: Rutaceae) (Supplementary Fig.\u0026nbsp;2B) known to attract newly mated mature queens (green colour). In this case, a new colony can reach maturity by 24\u0026ndash;36 months of growth (Peng et al., \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2012a\u003c/span\u003e; Ex\u0026eacute;lis et al., 2025b). Such colonies can be translocated to bagworms affected oil palm tree canopies to eradicate the infestation. Second is artificially rearing a colony by capturing a mature brood nest to place it at the top middle position of an affected bagworm oil palm tree trunk between the fronds (Supplementary Fig.\u0026nbsp;2A, red arrow). The translocated brood nest develops into a stable colony within one month, with the appearance of two more nests on average (Ex\u0026eacute;lis et al., 2025b).\u003c/p\u003e\u003cp\u003eWeaver ants poorly colonized the study area. Twenty brood nests were collected from the Calamansi orchard inside the oil palm plantation (Supplementary Fig.\u0026nbsp;2B-C). The orchard serves as a buffer zone promoting the growth and expansion of the weaver ant's incipient colonies (Lim, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The collection of brood nests (from mature colonies) was carried out preferably during rainy days, as this corresponds with the emergence of many reproductive individuals (Van Mele \u0026amp; Cuc, 2007; Nielsen et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2025a\u003c/span\u003e). During the lowest activity period of the weaver ant (sunrise), a single nest is cut from the tree (less than 2 meters high) (Peng et al., \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2012b\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), sealed tightly fast inside a large, hard fertilizer bag. We manipulated four highly \u003cem\u003eM. plana\u003c/em\u003e-affected (level 4) tagged plots of 1 ha each (Supplementary Fig.\u0026nbsp;3A-B) by posing and fixing the \u003cem\u003eO. smaragdina\u003c/em\u003e nests at the median side of the canopy base between the palm fronds for stability (Supplementary Fig.\u0026nbsp;2A). To avoid direct exposure to strong winds, each nest was placed at the lowest side of the canopy in the center for stability and to preserve nest integrity (corresponding to the top of the palm trunk tip) preferably three meters above the ground to resemble natural nesting site position (Crozier et al., 2010l Ex\u0026eacute;lis et al., 2025b). The nest was directly exposed to the morning light to promote nest building, foraging, and brood rearing. Each brood nest covers an average of 10 palm trees with an average range of 30\u0026ndash;85 total nests per colony (Ex\u0026eacute;lis et al., 2023b; Ex\u0026eacute;lis et al., 2025b) by establishing the artificial Line Bridge network to interconnect each canopy to one another (Peng et al., \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). This method facilitates the major workers\u0026rsquo; exploration crossover, promoting the colony\u0026rsquo;s expansion to adjacent palm canopies. Foragers initiated new nest construction within 24 hours (Supplementary Fig.\u0026nbsp;4A). Such colonies and workers will initiate fast nest construction and establishment (Offenberg, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). To enhance the possibility of trapping mated queens after rain (Nielsen et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Nene et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2016a\u003c/span\u003e), an artificial nesting network was established with natural palm frond leaflets (Offenberg, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) (Supplementary Fig.\u0026nbsp;4B). All bent palm fronds used to construct artificial trap leaflets nests (by binding them together to imitate the weaver ant nest construction technique), never returned to their initial high position. The higher canopy side nest location is significantly more suitable for attracting \u003cem\u003eO. smaragdina\u003c/em\u003e queens (Rwegasira et al., \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). The height above the ground defining the nest location in the canopy was fixed at an average of 4 m (Ex\u0026eacute;lis et al., 2025b). Honey and sucrose water (20% concentration), along with chicken intestines (as a protein artificial supplement booster), were provided once a week during one month (Peng et al., \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Nene et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2016b\u003c/span\u003e). To establish a strong \u003cem\u003eOecophylla\u003c/em\u003e colony, one planted host plant (Calamansi, citrus tree) per colony is necessary. To sustain one Asian weaver ant colony occupying an average range of 8\u0026ndash;12 oil palm trees, a single favorite host plant (citrus tree) is sufficient (Ex\u0026eacute;lis et al., 2025b). This information helps to know the number of brood nests needed to be translocated to any affected bagworm oil palm plot based on the total number of planted trees for further biological control application. If an area is planted with 100 oil palm trees, deploying 10 brood nests is sufficient protection for the targeted trial area. Since weaver ants are a territorial species, two palm trees were left empty between plots to prevent future fighting between distinct colonies.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3. Evaluation of biological control compared to chemical control\u003c/h2\u003e\u003cp\u003eThe trials consisted of three components: control plots without the Asian weaver ant and the TCI, the biological control strategy, and trunk injection chemical treatment. We compared three experimental conditions between (1) \u003cem\u003eO. smaragdina\u003c/em\u003e-occupied palm trees, (2) unoccupied palm trees consisting of the control plot critically affected by bagworms, and (3) the TCI treatment using two systemic insecticides, Krotofos 60 (monocrotophos 55% w/w) and multifos 60 (methamidophos 50 w/w), transported to foliage within hours to kill bagworms fast (Salim \u0026amp; Hamid, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Salim et al., \u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e2015b\u003c/span\u003e). Plots were monitored monthly to record the rate of damage done by bagworms and associate this damage with oil palm productivity/ quality by measuring and recording; (i) foliar injury level, (ii) monthly FFB yield, (iii) oil extraction rate (OER) preluding to fruits grade quality and (iv) the monthly incomes (Ringgit Malaysia RM). The foliar injury level was classified following Ex\u0026eacute;lis \u0026amp; Idris\u0026rsquo;s study (2013; Ex\u0026eacute;lis, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). The control plot produced fresh fruit bunches of low quality, rejected by mills processing factories. The palm tree canopies became skeletons (deprived of green leaves) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4. Bite protection \u0026ndash; Repellency \u0026ndash; Long-lasting effect (TTO)\u003c/h2\u003e\u003cp\u003eThe study was carried out following the purposive random sampling method. The host plant occupied by weaver ants in Felda Besout, Perak, Malaysia, and Banyuwangi, Indonesia, was selected. The trials were performed on large major workers (experimental unit), known to be more ferocious than smaller workers (Lim, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2025a\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), to evaluate the impact of pure organic tea tree essence oil extract drops to observe any nausea or escape reaction. The chemical originated from the Thursday Plantation Tea Tree Oil (TTO Australia), 100% pure organic, with a standard bioactive composition, under an act regulated by the ISO standard 4730. Weaver ant aggressive behavior (a 90ᵅ angle gaster elevation, Supplementary Fig.\u0026nbsp;7) was verified by placing the fingertips on the barrack nest of an occupied Indonesian Bayleaf tree, \u0026ldquo;Pohon Salam\u0026rdquo;, \u003cem\u003eSyzygium polyanthum\u003c/em\u003e Walp. (Myrtales: Myrtaceae) in Banyuwangi, Indonesia (8\u0026deg;27\u0026rsquo;19.4\u0026rdquo; S 114\u0026deg;07\u0026rsquo;05.7\u0026rdquo; E) (Supplementary Fig.\u0026nbsp;6b-c). The nest was disturbed by shaking it to create an emergency response from the colony's major workers. The control test was done directly by human presence without the TTO chemical. A preliminary test was carried out on 3 distinct colonies foraging trails at the base trunk by placing a filter paper disc treated with one pure drop of tea tree oil (TTO). All three replicates reacted positively by avoidance of the filter paper disc (N\u0026thinsp;=\u0026thinsp;10). As ants quickly showed rejection, a further test was conducted on the human body. One pure drop of TTO was applied to the hair, neck, arms, and legs of the ant-exposed human observer (first author), and was tested to verify its repelling effect on other \u003cem\u003eO. smaragdina\u003c/em\u003e colonies. The task involved positioning oneself at a very close distance (an average of 10 cm) from the main tree branches and placing the hands and arms on the weaver ant nests. We recorded the avoidance and biting behavior on an occupied single tree for each colony (N\u0026thinsp;=\u0026thinsp;10). The effect of the essential oil was evaluated immediately after application to the hands and wrists, then at 15, 30, 45 minutes, and one hour to verify contact persistence during the daily activity peaks corresponding to the hotter periods (1100 to 1530 hours). The experiment was repeated three times (See the two videos of the test from the Mendeley data link \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://data.mendeley.com/datasets/y4znm8mgz3/3\u003c/span\u003e\u003cspan address=\"https://data.mendeley.com/datasets/y4znm8mgz3/3\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, titled disturbed nest and tea tree pure extract repellency test).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.5. Statistical analysis\u003c/h2\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.5.1. BCA versus TCI data\u003c/h2\u003e\u003cp\u003eThe data set was pooled due to its large sample size (2019\u0026ndash;2022), which presented a skewed and kurtotic distribution, described as being more suitable (Kim, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). It was then summarized using descriptive statistics and is considered more accurate to replace the Shapiro-Wilk and Kolmogorov-Smirnov tests for large sample data (Kim, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Since the data variable response (income) is right-skewed, did not follow a normal distribution (Limpert et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Guisan et al., 2002; Coup\u0026eacute;, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Hastie, 2017), the Generalised Additive Model (GAM), flexible on the normality assumption (Wood, 2017), was applied with the link function identity and follows Ex\u0026eacute;lis et al\u0026rsquo;s method (2024). The response variable (\u003cem\u003eIncome\u003c/em\u003e) in this study is not normally distributed. Hence, GAM is applied with a gamma distribution using a log link function, which handles skewness naturally and ensures positive predictions (Kim, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Coup\u0026eacute;, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The GAM algorithm is being used for agricultural traits, such as wheat yield, and for solving problems like pest assessment, providing satisfactory insight into predictive events alongside factual ones (Marcillo et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The income data for five estate groups\u0026mdash;TCI OPP I to IV and BC Ants\u0026mdash;was analyzed using a second-degree polynomial regression model, incorporating a total of three predictors: Average Yield, OER (Oil Extraction Rate), and Total Yield. The modelling is performed on two predictor variables to obtain three distinct models, taking the incomes as the response factor. In model 1, the income is evaluated with the average yield and total yield metrics. Models 2 and 3 evaluated the combination of average yield and OER, then total yield and OER, respectively. Each model is subjected to an evaluation based on the Degree of Freedom (df), and the Akaike Information Criterion (AIC). To evaluate the adequacy of the GAM model with a Gamma distribution, AIC values are compared \u0026mdash; the lower the AIC, the better (Rubec et al., \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). The best model is also selected based on the significance of predictors, using a p-value threshold of 0.05. All the possible models are summarized, and the best among them is chosen based on evaluation metrics of the R-sq (adj), deviance explained, p-values, and AIC values (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eX\u003csub\u003e1\u003c/sub\u003e : Average_Yield_permth_ha; x\u003csub\u003e2\u003c/sub\u003e : Total_Yield_ton_perhectar; x\u003csub\u003e3\u003c/sub\u003e : dt\u003cspan\u003e$\u003c/span\u003eOER_percent and y : Incomes_RM. This method allowed for capturing non-linear relationships between the variables, average, total yield, and OER with the generated incomes. 240 observations of data were collected each year, totalling 960 records for four years (2019\u0026ndash;2022).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003ch2\u003e2.5.2 Tea Tree Oil evaluation\u003c/h2\u003e\u003cp\u003eIn this analysis, a logistic regression model with a binomial distribution and a logit link function is used to examine the relationship between the Bite variable (Bite\u0026thinsp;=\u0026thinsp;1, No Bite\u0026thinsp;=\u0026thinsp;0) as the response, and the Repel variable (Repel\u0026thinsp;=\u0026thinsp;1, No Repel\u0026thinsp;=\u0026thinsp;0) as the predictor. The logit link function used is defined as: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:logit\\left(p\\right)=\\frac{p}{1-p},\\:p\\left(\\text{0,1}\\right)\\)\u003c/span\u003e\u003c/span\u003e. Where log is the natural logarithm (base e), and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\frac{p}{1-p}\\)\u003c/span\u003e\u003c/span\u003e is called the odds of the event, and p is the probability of the event.\u003c/p\u003e\u003cp\u003eBoth the response and predictor variables are in binary form. Receiver Operating Characteristic (ROC) is a graphical tool used to evaluate the performance of a binary classification model, such as logistic regression. It assesses how well the model distinguishes between two classes (e.g., Bite\u0026thinsp;=\u0026thinsp;Yes/No) and is useful when class distribution is imbalanced. A confusion matrix was performed to compare the observed outcomes to the model\u0026rsquo;s predicted outcomes. We performed all statistical analyses using R version 4.3.3 (R Core Team, \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.1. \u003cem\u003eOecophylla\u003c/em\u003e-bagworms census\u003c/h2\u003e\u003cp\u003eAnts could neutralize \u003cem\u003eM. plana\u003c/em\u003e larvae (N\u0026thinsp;=\u0026thinsp;30) approaching their protected zone under darkness close to ant nests. The results of the monthly surveys provide this information (Supplementary Tables\u0026nbsp;1 and 2). The censuses provide information on the level of foliar injury and bagworm density, demonstrating the differences between occupied and unoccupied oil palms observed in the focused study area (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA-F; Supplementary Table\u0026nbsp;2). It is important to note that only the larval stage is responsible for foliar feeding, causing injury. The red arrows indicate the distribution of brood nests at the top-level positions of several palm tree canopies, ranging from 5 m to 7 m in height (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eE-F). Nests exhibit a well-constructed network with a prominent presence of heavy, whitish silk that closes off all exits (highlighted by the black arrow) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eE-F). In contrast, the palm fronds in occupied blocks appear healthy, with little to no observable injuries.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Experimental results: Trunk chemical injection versus biological control agent\u003c/h2\u003e\u003cp\u003eThe performance of the five plantation groups\u0026mdash;BC Ants, TCI OPP I, TCI OPP II, TCI OPP III, and TCI OPP IV\u0026mdash;was assessed based on key indicators, including average yield, oil extraction rate (OER), total yield, and income (Supplementary Table\u0026nbsp;4\u0026ndash;2019 to 2022). Biological control ants are the best performers with the highest median of total yield per hectare, with maximum and minimum yields, but still very much higher than the TCI OPP yield. For TCI, TCI OPP IV has the lowest median of yield per hectare. Both TCI OPP I and TCI OPP II have almost the same median of yield per hectare (Fig.\u0026nbsp;2A-D). Box plots are used to compare the median and variability of the data spread for average yield per month, total yield per hectare (ton), OER percentage, and income across the BCA and TCI groups. In most cases, the BCA group shows the most consistent variability, as the IQR values of the predictors (x\u003csub\u003e1\u003c/sub\u003e, x\u003csub\u003e2\u003c/sub\u003e, x\u003csub\u003e3\u003c/sub\u003e) are smaller than those of all the TCI groups (Figures A\u0026ndash;C). Figure D shows that the median income for the BCA group is significantly higher than that of the TCI groups.\u003c/p\u003e\u003cp\u003eWe summarize the performance of all groups to expose the overall results, showing a similar trend over four years. BC Ants significantly outperformed all TCI groups. With an average monthly yield of 15.50 t/ha and the highest OER (19.62%), BC Ants achieved the highest total yield (766.17 t) and total income (RM 327,430.76). The average monthly income for BC Ants was RM 27,285.90, more than triple the income of any TCI group. TCI OPP I and II performed moderately well, with yields of 4.89 and 4.56 t/ha/mo, respectively. The OERs were consistent with other TCI groups (~\u0026thinsp;17.7%), and their total incomes were RM 99,034.96 and RM 92,401.12. While they lagged significantly behind BC Ants, they maintained a moderate productivity level compared to the lower-performing TCI groups. TCI OPP III and IV displayed the lowest performance across all metrics. Their average yields were below 3.6 t/ha/mo, with monthly incomes under RM 6,000. This trend prevailed for the four years of treatment. The polynomial regression showed a high degree of accuracy in modeling estate income, indicated by an R\u0026sup2; score close to 0.99, suggesting that the model explains almost all variability in the income data. The Root Mean Squared Error (RMSE) shows low values across estates, implying minimal deviation between actual and predicted income (Supplementary Fig.\u0026nbsp;5A-D). BC Ants consistently recorded the highest average yield and total yield, resulting in significantly higher income values compared to TCI groups. TCI\u0026rsquo;s performance also showed less month-to-month variability. The income data for the four TCI OPP estates (I\u0026ndash;IV) and BC Ants estate over the years 2019 to 2022 shows noticeable differences in income levels, growth patterns, and volatility. All four TCI OPP estates demonstrate a generally increasing income trend from 2019 through 2022. However, the increases are modest when compared to BC Ants. BC Ants consistently records income figures far above the TCI OPP estates each year (Supplementary Tables\u0026nbsp;4 \u0026amp; 5; Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003eA-D). For instance, in 2020 and 2021, its monthly average often exceeded 30,000 while others stayed below 15,000. Despite its higher values, BC Ants displays a stable trend with relatively small variance month to month. The GAM evaluation shows that the income is postively associated with the three predictors, average, total yield and OER (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The graph in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the fitted income generated from the best model and the actual income. Graphically, it is observed that the actual data is clustered close to the predicted model (straight line). Hence, the fitted income data exhibited close similarity with the actual income data. The model x\u003csub\u003e1\u003c/sub\u003e, x\u003csub\u003e3\u003c/sub\u003e appears as the most fitted with lowest AIC (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, supplementary Table\u0026nbsp;5). The minimum income (RM 5064), and max income (RM 94,000), the error is only 9,000l; this is very good results (Supplementary Table\u0026nbsp;4). The variables x₁ and x₃ are significant predictors (p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05) for predicting income. Based on the deviance explained value, 89.1% of the variation in income can be explained by the model that includes only x₁ and x₃, in line with the principle of parsimony. Therefore, the full model, which includes all predictors, is not selected, as it is more complex without providing substantial improvement in model performance. The Generalized Additive Model (GAM) with a Gamma distribution and log link function provides a robust and well-fitting model for predicting income. The selected model includes two significant predictors (x1 and x3), both of which exhibit non-linear relationships with the response, as captured by the smooth terms. Diagnostic assessments, including residual plots, QQ plot of deviance residuals, and the deviance explained value, indicate that the model assumptions are reasonably satisfied. The model explains 89.1% of the deviance and achieves a high adjusted R\u0026sup2; of 0.844, suggesting excellent explanatory power. Based on the principle of parsimony and statistical significance, this reduced model is preferred over the full model. Therefore, the fitted GAM is both statistically adequate and practically interpretable for modelling income data with a right-skewed distribution.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePossible models of Generalised Additive Model with Gamma and log link function.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePredictor (s)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSignificant predictor\u003c/p\u003e\u003cp\u003e(P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDF\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAIC\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eAdj.R2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eDeviance explained\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e(0.0000)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e8.002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4857.652\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.838\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e84.4%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e2\u003c/sub\u003e(0.0000)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e7.071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4863.224\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.811\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e83.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e3\u003c/sub\u003e(0.0000)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.430\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e5090.171\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.556\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e57.9%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e, x\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e(0.0000); x\u003csub\u003e2\u003c/sub\u003e(0.9150)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e9.025\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4859.745\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.838\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e84.4%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e, x\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e(0.0000) ; x\u003csub\u003e3\u003c/sub\u003e(0.0000)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e18.904\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4789.762*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.844\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e89.1%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e2\u003c/sub\u003e, x\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e2\u003c/sub\u003e(0.0000) ; x\u003csub\u003e3\u003c/sub\u003e(0.0000)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e18.919\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4798.618\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.817\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e88.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e, x\u003csub\u003e2\u003c/sub\u003e, x\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ex\u003csub\u003e1\u003c/sub\u003e(0.0000) ; x\u003csub\u003e2\u003c/sub\u003e(0.5910) ; x\u003csub\u003e3\u003c/sub\u003e(0.0000)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e19.918\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4791.485\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.843\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e89.2%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: DF-degrees of freedom, AIC \u0026ndash; Akaike\u0026rsquo;s Information Criterion\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003ex\u003csub\u003e1\u003c/sub\u003e : Average_Yield_permth_ha; x\u003csub\u003e2\u003c/sub\u003e : Total_Yield_ton_perhectar; x\u003csub\u003e3\u003c/sub\u003e \u0026lt;- dt$OER_percent\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003ey: Incomes_RM (response variable). *The best model\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.4. Bite nuisance protection, repellency, and long-lasting effect: TTO\u003c/h2\u003e\u003cp\u003eThe major workers approached and climbed the hand posed on their nests. Whenever the tea tree essential oil was not used as a protective shield, a plethora of workers came instantly to bite relentlessly. In contrast, no ant bites were recorded during all the repeated tests carried out under tea tree oil spread throughout the hand and arm (N\u0026thinsp;=\u0026thinsp;90 for three replicates) except for only one incidence (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003e \u0026ndash; Bite over time). Few workers came to attack while the majority stood far from the hand. However, aggressive stances were exhibited by the mandible widely open with the gaster 90\u0026deg;angle elevation marking their territorial characteristic behavior in a swift response to the encroachment (Supplementary Fig.\u0026nbsp;6a, Fig.\u0026nbsp;7). The tea tree essential oil demonstrated a powerful repelling effect on the major workers causing avoidance and a rare bites absence behavior (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003e). This oil possesses a deterrent odor, having the quality of residual contact persistence for up to one hour upon first application on the body (See the two videos of the test from the Mendeley data link \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://data.mendeley.com/datasets/y4znm8mgz3/3\u003c/span\u003e\u003cspan address=\"https://data.mendeley.com/datasets/y4znm8mgz3/3\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, titled disturbed nest and tea tree pure extract repellency test). The very large negative coefficient value exp (\u0026minus;\u0026thinsp;21.87)\u0026thinsp;=\u0026thinsp;3.1 x 10\u003csup\u003e\u0026minus;\u0026thinsp;10\u003c/sup\u003e is close to zero probability of a bite when repelled. Repel\u0026thinsp;=\u0026thinsp;1 almost completely prevents bites. However, the huge standard error (7030) and p value\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;.998 indicate that this result is not statistically significant. This is likely due to perfect separation and or medium sample size. The area under the curve (AUC) is 0.98, which means the model has a 98% chance of ranking a randomly chosen \"positive\" case higher than a \"negative\" one (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003e). That is excellent performance. In general, the model accuracy is 96%. The model correctly predicts most \"No Bite\" cases and does not miss any \"Bite\" cases. The precision is low (only 1 out of 3 predicted bites was correct).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThis study is the first applied research method conducted in a large open-field oil palm plantation to evaluate a biological control agent (BCA). The Asian weaver ant is well-documented for its effectiveness in dealing with diverse pests of economic importance that are harmful to commercial crops (Offenberg, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Foliar injury is severe, with 462.30 cm\u003csup\u003e2\u003c/sup\u003e scraped and cut leaves representing 2.794 g of removed biomass by \u003cem\u003eM. plana\u003c/em\u003e instar larvae (Tuck et al., \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). The BCA treatment demonstrated the control of the invasive and poly-phytophagous bagworm over 4.5 yearly life cycle generations (average 75 days \u0026ndash; Tuck et al, \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Enting \u0026amp; Latip, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), corresponding to 18 generations (over 4 years).\u003c/p\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003e4.1. Control method impacts: productivity, quality, and yield-profit\u003c/h2\u003e\u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\u003ch2\u003e4.1.1 Current method \u0026ndash; Management cost (Ringgit Malaysia)\u003c/h2\u003e\u003cp\u003eThe current method of controlling bagworms includes injecting oil palm trunks with systemic organophosphate (which produces lethal effects on pests eating leaves) and aerial spraying of biopesticides (such as \u003cem\u003eBacillus thuringiensis\u003c/em\u003e). The protocol treatment includes pyrethroids (cypermethrin and deltamethrin) with selective pesticides (lead arsenate) and trichlorfon (Wood \u0026amp; Norman, \u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e2019a\u003c/span\u003e; \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e2019b\u003c/span\u003e). Cypermethrin and deltamethrin are highly toxic to aquatic animals (Khompun et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), and their environmental persistence seriously threatens humans (Ullah et al., \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The cost induced by these methods is much higher than the usage of the Asian weaver ant. With an estimated RM 0.70 bagworm TCI cost per palm (Salim et al., \u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e2015b\u003c/span\u003e) and a density of 136\u0026ndash;160 oil palm trees per hectare, the average cost is RM 95,000.00 to RM 112,000.00 for a 1000-ha plantation during a severe infestation outbreak. \u003cem\u003eBacillus thuringiensis\u003c/em\u003e (Bt) aerial spraying by drones engages consequent investment that is not affordable by most of the smallholding plantation owners (Masri et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Sticky traps using female pheromones to lure male individuals into the infested oil palm blocks generated a substantial decline in the male moth population, offered an affordable cost to smallholders (Norman \u0026amp; Othman, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Mohd Najib et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Noorhazwani et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). The information on the benefit-cost of pest control management and the study of pesticide persistence in the agro environment is scarce and limited in open field plantations (Muhamad et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Sulaiman et al., 2020). The cost-benefit studies comparing \u003cem\u003eOecophylla\u003c/em\u003e BCA to conventional methods are scarce. Peng \u0026amp; Christian (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2005b\u003c/span\u003e), and Offenberg et al (\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) are among the rare detailed evaluations with valuable information on this matter.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section3\"\u003e\u003ch2\u003e4.1.2 BCA versus TCI\u003c/h2\u003e\u003cp\u003eThe damages incurred by the bagworm on the unoccupied control plot without the TCI severely affected their FFB grade, resulting in all fruits being rejected and not acceptable for the mill palm oil processing industries. Defined by the OER level, the FFB grade was lower in TCI treatments, while the BCA treatment gave a significantly higher quality for the four years of data record. The significant increase in productivity, quality, and annual yield after the introduction of weaver ants is consistent with other reports from Australia (Peng et al., \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2012a\u003c/span\u003e; Forbes \u0026amp; Northfield, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), the Philippines (Pag-Ong, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), China and Vietnam (Van Mele \u0026amp; Cuc, \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Peng et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), Thailand (Offenberg et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), Indonesia (Ridwan et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), and Africa (Van Mele et al., \u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Peak yields tend to occur around March\u0026ndash;May and September\u0026ndash;November, aligning with bimodal rainfall seasonal patterns in tropical regions (Mumo et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The biological control of fruit plantations using \u003cem\u003eOecophylla\u003c/em\u003e spp. has been well-documented in Australia and Asia (Krag et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Peng \u0026amp; Christian, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Peng \u0026amp; Christian, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). A study by Peng \u0026amp; Christian (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2005b\u003c/span\u003e) demonstrated the higher yield and profit resulting from using Asian weaver ants compared to the relatively limited impact of chemical insecticides in Australian mango orchards. The cost-effectiveness of ant control and significant harvest incomes were also observed in Vietnamese citrus orchards. However, in Thai mango blocks, biological control failed due to fruit-setting destruction by the leafhopper \u003cem\u003eIdioscopus clypealis\u003c/em\u003e (Offenberg et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e4.2. The manipulations and deployment of weaver ant nests in oil palm plantations\u003c/h2\u003e\u003cp\u003eBased on field experiences, capturing nests is most effective between 2200 hours and 0600 hours (Lim, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Ex\u0026eacute;lis et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). During this time, ants are slower, less aggressive, and less likely to launch aggressive attacks on intruders. Spending time under a palm tree with a heavy presence of \u003cem\u003eOecophylla\u003c/em\u003e nests can be challenging (Ex\u0026eacute;lis et al., 2023b; Ex\u0026eacute;lis et al., 2025b). It is possible to swiftly remove a single nest from a short palm tree and relocate it within the same plantation. Careful handling with appropriate disposable materials is necessary when sampling brood nests that contain a high abundance of ant individuals across all castes. Introducing the captured nest on a new palm tree affected by bagworm defoliators, along with chicken, has proven effective. Transferring nests over long distances for biological control trials is not recommended. The newly introduced biological control agent could act similarly to an exotic species. Risks to human, animal, and plant health and potential environmental damages have been reported (De Clercq et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Reduction of other natural native enemies is reported in multiple cases in both tropical and temperate climate countries (Van Lenteren et al., \u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e2006\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\u003ch2\u003e4.3 Bite protection \u0026ndash; Repellency \u0026ndash; Long lasting effect (TTO)\u003c/h2\u003e\u003cp\u003eAn alternative approach to mitigate ant attacks is to employ natural insect repellents. \u003cem\u003eMelaleuca alternifolia\u003c/em\u003e tea tree is a novelty, and few studies have reported similar breakthroughs from the application of oils to repel \u003cem\u003eO. longinoda\u003c/em\u003e in Senegal (Chailleux et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The essence oil's bioactive compounds (i.e., terpenes and tertiary alcohols) provide a strong defensive function to the plants, resulting in expelling insect intruders or causing mortality (Buteler et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Generally, essential oils are vulnerable to demonstrating low persistence in the environment due to fast volatilization and oxidative degradation from heat and light (El et al., 2015). The Asian weaver ant's foraging activity disruption, causing instant bite nuisance nullity, is a breakthrough finding. TTO application on hands, neck, and head provided full protection from ant bite nuisance, repelled ferocious major workers with a long lasting effect (one hour). Venturing into territories dominated by \u003cem\u003eO. smaragdina\u003c/em\u003e consistently resulted in ant bites and immediate aggression. Ecological damage incurred to the environment by synthetic pesticides is well documented, and the application of BCA throw selective natural enemies for augmentative biological control is becoming more widespread worldwide (Van Lenteren et al., \u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The efforts to reduce reliance on manual human harvesters are timely (Radzi et al., \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), hence minimizing ant bites.\u003c/p\u003e\u003c/div\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThe study discovered that maintaining a sufficient numerical ratio between weaver ant predator-defoliators and foragers, favoring the latter, facilitates the effective suppression of invasive bagworms. The healthy green foliage in occupied palms contrasted strongly with the skeletal sight of unoccupied canopies. The FFB productivity and quality improve with higher monthly incomes. The innovation of \u003cem\u003eM. alternifolia\u003c/em\u003e tea tree essential oil as an aggressively effective weaver ant repellent vector opens new alternatives. The future adoption of the Asian weaver ant for better, and environmentally friendly, and cheaper cost pest management in the tropical agro-systems of Asia. Consequently, the study concludes that adopting Asian weaver ant colonies is a feasible and productive strategy that offers smallholders in the oil palm industry an affordable and effective means of controlling the invasive bagworm \u003cem\u003eMetisa plana\u003c/em\u003e.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eDECLARATION OF COMPETING INTEREST\u003c/h2\u003e\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eSUPPLEMENTARY INFORMATION\u003c/h2\u003e\u003cp\u003eThe supporting information is provided in this manuscript.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFUNDING\u003c/h2\u003e\u003cp\u003eDECLARATION\u003c/p\u003e\u003cp\u003eThis study did not receive funding for support.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eEx\u0026eacute;lis Mo\u0026iuml;se Pierre: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Prepared tables/figures, Project administration, Resources, Validation, Visualization, Writing \u0026ndash; Original Draft, Writing \u0026ndash; Review \u0026amp; Editing. Rosli Ramli: Project administration, Resources, Supervision, Writing \u0026ndash; Review \u0026amp; Editing. Roslinazairimah Zakaria: Formal analysis, Methodology, Software, Visualization, Writing \u0026ndash; Review \u0026amp; Editing. Azarae Hj Idris: Investigation, Project administration, Resources, Supervision, Writing \u0026ndash; Original Draft. Rabha W. Ibrahim: Formal analysis, Methodology, Software, Visualization, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis study is a part of the first author\u0026rsquo;s PhD dissertation supported under a French-European Union complete scholarship grant through the local government authority of \u0026ldquo;Collectivit\u0026eacute; Territoriale de la Martinique-CTM\u0026rdquo; in the Meso-American Caribbean (awarded to EMP). Special thanks to the Malaysian Palm Oil Board (MPOB), Federal Land Development Authority FELDA Malaysia, Universiti Malaya Oil Palm Research Center Sdn. Bhd for granting access permission to its facilities and plantations in Malaysia. We are grateful for the helpful reviews performed by Dr. Eric Wajnberg, Editor in Chief of BioControl Journal, and Dr. Francis P. F. Reay-Jones, Receiving Editor of Crop Protection Journal. Special thanks to the management of \u0026ldquo;Surau An-Nur, section 20 Shah Alam Selangor State, Malaysia\u0026rdquo; for providing accommodation and daily services, helping to sustain the needs during the writing and correction period of the manuscript. EMP received a doctoral scholarship from the local government authority of the Martinique Island \u0026ldquo;Collectivit\u0026eacute; Territoriale de la Martinique-CTM.\u0026rdquo;, under a French-European Union scheme, financial support (overseas travel, accommodation, daily life cost \u0026ndash; not project funding) for students originating from the Caribbean Islands.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data presented in this study are openly available in this manuscript and can be retrieved in the below link (Raw dataset BCA vs TCI and videos disturbed nest \u0026ndash; tea tree pure extract repellence positive test): https://data.mendeley.com/datasets/y4znm8mgz3/3\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAdhawiyah, N. R., Noorhazwani, K., Bakeri, S. A., Zainuddin, N., Keni, M. F., \u0026amp; Masri,M. M. M. (2023). Impact of environmental factors on the larval population of bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) in oil palm smallholdings. Serangga, 28(2): 149\u0026ndash;161.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBasri, A.H. H., Girsang, S. A. \u0026amp; Novita, A.(2022). The Impact of bagworm (\u003cem\u003eMetisa plana\u003c/em\u003e) attacks on oil palm (\u003cem\u003eElaeis guineensis\u003c/em\u003e Jacq.) production at Tanjung Beringin Plantation, PT. Langkat Nusantara Kepong, Indonesia. International Journal of Biosciences and Biotechnology 10(1): 1\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBedini, S., Cosci, F., Tani, C., Pierattini, E. C., Venturi, F., Lucchi, A., \u0026amp; Ioriatti, C et al. (2020). \"Essential oils as post-harvest crop protectants against the fruit fly \u003cem\u003eDrosophila suzukii\u003c/em\u003e: Bioactivity and organoleptic profile.\" Insects, 11, no. 8: 508.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eButeler, M., Alma, A. M., Herrera, M. L., Gorosito, N. B., \u0026amp; Fern\u0026aacute;ndez, P. C. (2021). Novel organic repellent for leaf-cutting ants: tea tree oil and its potential use as a management tool. \u003cem\u003eInternational Journal of Pest Management\u003c/em\u003e, \u003cem\u003e67\u003c/em\u003e(1), 1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChailleux, A., Stirnemann, A., Leyes, J., \u0026amp; Deletre, E. (2019). \"Manipulating natural enemy behavior to improve biological control: attractants and repellents of a weaver ant.\" Entomologia Generalis, 38: 191\u0026ndash;210..\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChe Hussian, C. H. A., Seman-Kamarulzaman, A. F., Othman, N. W., Nor Muhammad, N. A., Jalinas, J., Zainal Abidin, C. M. R., \u0026hellip; Hassan, M. (2025). Global research trends in oil palm pests and their potential threat: a bibliometric analysis. \u003cem\u003eInternational Journal of Pest Management\u003c/em\u003e, 1\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCoup\u0026eacute;, C. (2018). Modeling linguistic variables with regression models: Addressing non-Gaussian distributions, non-independent observations, and non-linear predictors with random effects and generalized additive models for location, scale, and shape. \u003cem\u003eFrontiers in psychology\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e, 513.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Clercq, P., Mason, P. G., \u0026amp; Babendreier, D. (2011). Benefits and risks of exotic biological control agents. BioControl, \u003cem\u003e56\u003c/em\u003e, 681\u0026ndash;698.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEl Asbahani, A., Miladi, K., Badri, W., Sala, M., Addi, E. A., Casabianca, H., \u0026hellip; Elaissari, A. (2015). Essential oils: From extraction to encapsulation. International journal of pharmaceutics, \u003cem\u003e483\u003c/em\u003e(1\u0026ndash;2), 220\u0026ndash;243.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEnting, C. E., \u0026amp; Latip, S. N. H. M. (2021). Life cycle of oil palm bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) at different temperatures under controlled environment. Serangga 2021, 26(2): 151\u0026ndash;165.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M. P. (2014). An ecological study of \u003cem\u003ePteroma pendula\u003c/em\u003e (Lepidoptera: Psychidae) in oil palm plantations with emphasis on the predatory activities of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) on the bagworm. Master Dissertation, Universiti Malaya, Kuala Lumpur, Malaysia.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M. P., \u0026amp; Idris, A. H. (2013). Studies on the predatory activities of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) on \u003cem\u003ePteroma pendula\u003c/em\u003e (Lepidoptera: Psychidae) in oil palm plantations in Teluk Intan, Perak (Malaysia). Asian Myrmecology, 5, 163\u0026ndash;176.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis M. P., Ramli, R., Idris, A. H., \u0026amp; Sani, M. S. A. (2022). Estimation of worker population size-density by nest counting in the Asian weaver ant, \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Formicidae: Formicinae) and its dynamic in oil palm plantations industry. 2022, preprint-researchsquare. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.21203/rs.3.rs-2321637/v1\u003c/span\u003e\u003cspan address=\"10.21203/rs.3.rs-2321637/v1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M.P.; Ramli, R.; Ibrahim, R.W.; Idris, A.H. (2023a). Foraging Behaviour and Population Dynamics of Asian Weaver Ants: Assessing Its Potential as Biological Control Agent of the Invasive Bagworms \u003cem\u003eMetisa plana\u003c/em\u003e (Lepidoptera: Psychidae) in Oil Palm Plantations. Sustainability, 15, 780. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/su15010780\u003c/span\u003e\u003cspan address=\"10.3390/su15010780\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis. M. P., Ramli, R., Idris, A. H., Ibrahim, W. R., \u0026amp; Clemente-Orta, M. G. (2023b). Distribution and Nest Occupancy Patterns of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) Colonies in Southeast Asia Oil Palm Plantations. Preprints.org, 2023040057.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.20944/preprints202304.0057.v1\u003c/span\u003e\u003cspan address=\"10.20944/preprints202304.0057.v1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M. P., Ramli, R., Hj Idris, A., Zakaria, R., Yacob, Z., Ibrahim, R. W., Yaakop, S., \u0026amp; Othman, N. W. (2023c). The Social Organisation of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) Colonies and Their Functional Activity. Preprints, 2023040067. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.20944/preprints202304.0067.v1\u003c/span\u003e\u003cspan address=\"10.20944/preprints202304.0067.v1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M. P., Ramli, R., Latif, S. A. A., Idris, A. H., Clemente-Orta, G., \u0026amp; Kermorvant, C. (2024). Elucidating the daily foraging activity pattern of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e to minimize bite nuisances in Asia large agro-system plantations. \u003cem\u003eHeliyon\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(4).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis, M. P., Ramli, R., Azarae, H. I., Roslinazairimah, Z., Zubaidah, Y., Rabha, W. I., Salmah, Y., \u0026amp; Nurul Wahida, O. (2025a). The social organization of the Asian weaver ant colonies: A natural enemy novel sub-castes worker\u0026rsquo;s functional activity findings. In Press, PlosOne. DOI: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1371/journal.pone.0326030\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0326030\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEx\u0026eacute;lis. M. P., Ramli, R., Idris, A. H., Ibrahim, W. R., \u0026amp; Clemente-Orta, M. G. (2025b). Distribution and Nest Occupancy Patterns of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) Colonies in Southeast Asia Oil Palm Plantations. \u003cem\u003eAsia-Pacific Entomology Journal\u003c/em\u003e. Accepted for publication (not in Press yet). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.20944/preprints202304.0057.v1\u003c/span\u003e\u003cspan address=\"10.20944/preprints202304.0057.v1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eForbes, S. J., \u0026amp; Northfield, T. D. (2017). \"\u003cem\u003eOecophylla smaragdina\u003c/em\u003e ants provide pest control in Australian cacao.\" Biotropica, 49(3), 328\u0026ndash;336.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKalidas, P. (2012). Pest problems of oil palm and management strategies for sustainability. Agrotechnology, \u003cem\u003eS11\u003c/em\u003e, \u003cem\u003e1\u003c/em\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKamarudin, N., Ali, S. R. A., Masri, M. M. M., Ahmad, M. N., \u0026amp; Manan, C. A. H. C. (2017). Controlling \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) outbreak using \u003cem\u003eBacillus thuringiensis\u003c/em\u003e at an oil palm plantation in Slim River, Perak, Malaysia. Journal Oil Palm Research, 29 (1), 47\u0026ndash;54.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKhompun, W., Chonlada, D., T., \u0026amp; Waraporn, C. (2024). \"Accumulation and Phytotoxicity of Cypermethrin and Deltamethrin to Aquatic Plants.\" \u003cem\u003ePertanika Journal of Tropical Agricultural Science\u003c/em\u003e, 47(1).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKim, H. Y. (2013). Statistical notes for clinical researchers: assessing normal distribution (2) using skewness and kurtosis. \u003cem\u003eRestorative dentistry \u0026amp; endodontics\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(1), 52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKrag, K., Lundegaard, R., Offenberg, J., Nielsen, M.G., \u0026amp; Wiwatwittaya, D. (2010). \"Intercolony transplantation of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) larvae.\" Journal of Asia-Pacific Entomology, 13, (2), 97\u0026ndash;100.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLim, G.T. (2007). Enhancing the weaver ant, \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae), for biological control of a shoot borer, \u003cem\u003eHypsipyla robusta\u003c/em\u003e (Lepidoptera: Pyralidae), in Malaysian mahogany plantations. Doctoral Dissertation, Virginia Tech University, USA. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://vtechworks.lib.vt.edu/handle/10919/26850\u003c/span\u003e\u003cspan address=\"https://vtechworks.lib.vt.edu/handle/10919/26850\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLimpert, E., Stahel, W. A., \u0026amp; Abbt, M. (2001). Log-normal distributions across the sciences: keys and clues: on the charms of statistics, and how mechanical models resembling gambling machines offer a link to a handy way to characterize log-normal distributions, which can provide deeper insight into variability and probability\u0026mdash;normal or log-normal: that is the question. \u003cem\u003eBioScience\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(5), 341\u0026ndash;352.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMarcillo, G. S., Martin, N. F., Diers, B. W., Da Fonseca Santos, M., Leles, E. P., Chigeza, G., \u0026amp; Francischini, J. H. (2021). Implementation of a generalized additive model (Gam) for soybean maturity prediction in african environments. \u003cem\u003eAgronomy\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(6), 1043.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMasri, M. M. M., Kamarudin, N., Napiah, N. R. M. A., \u0026amp; Keni, M. F. (2022). Effectiveness of \u003cem\u003eBacillus thuringiensis\u003c/em\u003e aerial spraying against the bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) outbreak in oil palm using drone. Journal of Oil Palm Research, 34(2), 276\u0026ndash;288.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMohd Najib, A., Kamarudin, N., Ahmad, S. N., Arshad, O., Masri, M. M. M., Moslim, R., \u0026amp; Kushairi, A. (2017). Efficacy of pheromone trapping and aerial spraying of \u003cem\u003eBacillus thuringiensis\u003c/em\u003e (Bt) for controlling bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) in Yong Peng, Johor, Malaysia. Journal of Oil Palm Research, \u003cem\u003e29\u003c/em\u003e(1), 55\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMuhamad, H., Ramli, M. I., Zakaria., \u0026amp; Sahid, I. (2013). The fate of diuron in soil in a Malaysian oil palm plantation. Journal of Oil Palm Research, \u003cem\u003e25\u003c/em\u003e(1), 149\u0026ndash;158.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMumo, L., Yu, J., \u0026amp; Fang, K. (2018). Assessing impacts of seasonal climate variability on maize yield in Kenya. \u003cem\u003eInternational Journal of Plant Production\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(4), 297\u0026ndash;307.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNene, W. A., Rwegasira, G. M., Nielsen, M. G.; Mwatawala, M., \u0026amp; Offenberg, J. (2016a). Nuptial flights behavior of the African weaver ant, \u003cem\u003eOecophylla longinoda\u003c/em\u003e Latreille (Hymenoptera: Formicidae) and weather factors triggering flights. Insectes sociaux, 63(2), 243\u0026ndash;248.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNene, W., Rwegasira, G. M., Mwatawala, M., Nielsen, M. G., \u0026amp; Offenberg, J. (2016b). Foraging behavior and Preferences for Alternative Supplementary Feeds by the African Weaver Ant, \u003cem\u003eOecophylla longinoda\u003c/em\u003e Latreille (Hymenoptera, Formicidae). Journal of Hymenoptera Research, 50, 117\u0026ndash;128.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNielsen, M. G., Peng, R., Offenberg, J., \u0026amp; Birkmose, D. (2016). Mating strategy of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) in northern Australia. Austral Entomology, 55(3), 261\u0026ndash;267.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNoorhazwani K,, Siti Nurulhidayah A, Mohd Najib A, Mohd Fahmi, K., Nur Robaatul Adhawiyah, M. A. N., Shamsilawani, A. B., Mohamad, R. S \u0026amp; Mohamed, M. M. (2024). Quad Trap: An Alternative Approach to increase trapping efficiency of the male bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker. Special issue: 5th INTERNATIONAL SYMPOSIUM ON INSECTS (ISOI2023), \u0026ldquo;UNVEILING THE HIDDEN PROSPECT OF INSECTS\u0026rdquo;, 11\u0026ndash;13 SEPTEMBER 2023. Serangga, 29(2): 177\u0026ndash;188.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNorman, K., \u0026amp; Othman, A. (2016). Diversity and activity of insect natural enemies of the bagworm (Lepidoptera: Psychidae) within an oil palm plantation in Perak, Malaysia. \u003cem\u003eJournal of oil Palm research\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e(3), 296\u0026ndash;307.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOffenberg, J. (2014). The use of artificial nests by weaver ants: A preliminary field observation. Asian Myrmecology, 6(1), 6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOffenberg, J. (2015). \"Ants as tools in sustainable agriculture.\" Journal of Applied Ecology, 52, no. 5: 1197\u0026ndash;1205.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOffenberg, J., Cuc, N. T. T., \u0026amp; Wiwatwitaya, D. (2013). The effectiveness of weaver ant (\u003cem\u003eOecophylla smaragdina\u003c/em\u003e) biocontrol in Southeast Asian citrus and mango. Asian Myrmecology, 5, 139\u0026ndash;149.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePag-Ong, Anthony Ian. (2021). \"Taxonomy and diversity of ants associated with cacao and evaluation of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e Fabricius (Hymenoptera: Formicidae) for biological control of \u003cem\u003eHelopeltis bakeri\u003c/em\u003e Poppius (Hemiptera: Miridae) in Quezon and Laguna, Philippines.\" Doctorate dissertation, De La Salle University, Manila Philippines.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R. K., \u0026amp; Christian, K. (2005a). Integrated pest management in mango orchards in the Northern Territory Australia, using the weaver ant, Oecophylla smaragdina,(Hymenoptera: Formicidae) as a key element. \u003cem\u003eInternational Journal of Pest Management\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(2), 149\u0026ndash;155.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R. K., \u0026amp; Christian, K. (2005b). The control efficacy of the weaver ant, \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae), on the mango leafhopper, \u003cem\u003eIdioscopus nitidulus\u003c/em\u003e (Hemiptera: Cicadellidea) in mango orchards in the Northern Territory. International Journal of Pest Management, 51(4), 297\u0026ndash;304.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R. K., \u0026amp; Christian, K. (2006). Effective control of Jarvis\u0026rsquo;s fruit fly, \u003cem\u003eBactrocera jarvisi\u003c/em\u003e (Diptera: Tephritidae), by the weaver ant, \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae), in mango orchards in the Northern Territory of Australia. International Journal of Pest Management, 52(4), 275\u0026ndash;282.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R. K., \u0026amp; Christian, K. (2007). The effect of the weaver ant, \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae), on the mango seed weevil, \u003cem\u003eSternochetus mangiferae\u003c/em\u003e (Coleoptera: Curculionidae), in mango orchards in the Northern Territory of Australia. International Journal of Pest Management, 53(1), 15\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R. K., Christian, K., \u0026amp; Gibb, K. (2004). \"Implementing Ant Technology in Commercial Cashew Plantations and Continuation of Transplanted Green Ant Colony Monitoring: A Report for the Rural Industries Research and Development Corporation, Australian government.\" RIRDC Publication No W04/088.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R., Christian, K., \u0026amp; Reilly, D. (2012a). Biological control of the fruit-spotting bug \u003cem\u003eAmblypelta lutescens\u003c/em\u003e using weaver ants \u003cem\u003eOecophylla smaragdina\u003c/em\u003e on African mahoganies in Australia. Agricultural and Forest Entomology, 14(4) 428\u0026ndash;433.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R., Christian, K., \u0026amp; Gibb, K. (2012b). The best time of day to monitor and manipulate weaver ant colonies in biological control. Journal of Applied Entomology, \u003cem\u003e136\u003c/em\u003e(1-2), 155\u0026ndash;160.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, R., Lan, L.P., \u0026amp; Christian, K. (2014). Weaver Ant Role in Cashew Orchards in Vietnam. Journal of Economic Entomology, 107(4), 1330\u0026ndash;1338.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRadzi, M. K. F. M., Khalid, M. R. M., Azaman, M. I. H., Mohamed, A., Thadeus, D. J., \u0026amp; Bakri, M. A. M. (2023). The Initiative to Further Enhance Technology Adoption in the Malaysian Oil Palm Industry. \u003cem\u003eAdvances in Agricultural and Food Research Journal\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(2).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eR Core Team. (2024). R: A language and environment for statistical computing (Version 4.3.3) [Software]. R Foundation for Statistical Computing. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.R-project.org/\u003c/span\u003e\u003cspan address=\"https://www.R-project.org/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRidwan, A., Nurariaty A., \u0026amp; Tamrin, A. M. (2019). \"Exposure Test of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Hymenoptera: Formicidae) for Controlling Damage from \u003cem\u003ePrays Endocarpa\u003c/em\u003e (Lepidoptera: Yponomeutidae) on Pummelo (\u003cem\u003eCitrus Maxima\u003c/em\u003e Merr.).\" International Journal of Scientific Research in Science and Technology, 6(6), 289\u0026ndash;295. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.32628/IJSRST196663\u003c/span\u003e\u003cspan address=\"10.32628/IJSRST196663\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRubec, P. J., Kiltie, R., Leone, E., Flamm, R. O., McEachron, L., \u0026amp; Santi, C. (2016). Using delta-generalized additive models to predict spatial distributions and population abundance of juvenile pink shrimp in Tampa Bay, Florida. \u003cem\u003eMarine and coastal fisheries\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(1), 232\u0026ndash;243.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRwegasira, R. G., Maulid, M., Rwegasira, G. M., Nielsen G. M, \u0026amp; Offenberg, J. (2015). \"Comparing different methods for trapping mated queens of weaver ants (\u003cem\u003eOecophylla longinoda\u003c/em\u003e; Hymenoptera: Formicidae).\" Biocontrol Science and Technology, 25(5), 503\u0026ndash;512.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSalim, H., \u0026amp; Hamid, N. H. (2012). Evaluation of several chemical control approaches against bagworm, \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) in Felda oil palm plantations. Plant, 88, 785\u0026ndash;799.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSalim, H., Rawi, C. S. M., Hamid, N. H., Ismail, S. T., Abidin, C. M. R. Z., \u0026amp; Ahmad, A. H. (2015b). Efficacy of trunk injection technique of systemic insecticide against bagworms on oil palm. Advances in Environmental Biology, 9(27), 129.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSulaiman, S. S. (2020). Regulating good agriculture practices (Gaps) in enhancing sustainability of halal food: Malaysian experience. \u003cem\u003eMalaysian Journal of Consumer and Family Economics\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(2), 32\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSyarif, M.N.Y., Asib, N., Ahmad, S.N., Bakeri, S.A. \u0026amp; Mazmira, M.M.M. 2023. Identification of \u003cem\u003eCordyceps javanica\u003c/em\u003e and its effectiveness in controlling bagworm, \u003cem\u003ePteroma pendula\u003c/em\u003e Joannis (Lepidoptera: Psychidae). Serangga 28(2): 14\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTing, A., Abidin, C. M, Hamid, N. H., Azzam, G., \u0026amp; Salim, H. (2023). Uncovering the Microbiota of Bagworm \u003cem\u003eMetisa plana\u003c/em\u003e (Lepidoptera: Psychidae) in Oil Palm Plantations in Malaysia. Tropical Life Sciences Research, 34(1):185.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTuck, H. C., Ibrahim, Y., \u0026amp; Chong, K. K. (2010). Comparative life histories, demographic statistics and damage potential of the bagworms \u003cem\u003ePteroma pendula\u003c/em\u003e and \u003cem\u003eMetisa plana\u003c/em\u003e in oil palm. Journal of Science and Mathematics Letters, \u003cem\u003e2\u003c/em\u003e(2), 39\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUllah, S., Zuberi, A., Alagawany, M., Farag, M. R., Dadar, M., Karthik, K., \u0026hellip; Iqbal, H. M. (2018). Cypermethrin induced toxicities in fish and adverse health outcomes: Its prevention and control measure adaptation. Journal of Environmental Management, \u003cem\u003e206\u003c/em\u003e, 863\u0026ndash;871.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Lenteren, J. C., Bale, J., Bigler, F., Hokkanen, H. M. T., \u0026amp; Loomans, A. J. M. (2006). Assessing risks of releasing exotic biological control agents of arthropod pests. Annual review of entomology, \u003cem\u003e51\u003c/em\u003e(1), 609\u0026ndash;634.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Lenteren, J. C., Bolckmans, K., K\u0026ouml;hl, J., Ravensberg, W. J., \u0026amp; Urbaneja, A. (2018). Biological control using invertebrates and microorganisms: plenty of new opportunities. BioControl, \u003cem\u003e63\u003c/em\u003e, 39\u0026ndash;59.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Mele, P. (2008). A historical review of research on the weaver ant \u003cem\u003eOecophylla\u003c/em\u003e in biological control. Agricultural and Forest Entomology, 10, 13\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Mele, P., \u0026amp; Cuc, N. T. T. (2000). Evolution and status of \u003cem\u003eOecophylla smaragdina\u003c/em\u003e (Fabricius) as a pest control agent in citrus in the Mekong Delta, Vietnam. International Journal of Pest Management, 46, 295\u0026ndash;301.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Mele, P. \u0026amp; Cuc, N. T. T. (2007). Ants as Friends: Improving your Tree Crops with Weaver Ants (2nd Edition). Africa Rice Center (WARDA), Cotonou, Benin, and CABI, Egham, UK. 72 pp.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Mele, P., Nguyen, T. T. C.; Seguni, Z., Camara, K., \u0026amp; Offenberg, J. (2009). Multiple sources of local knowledge: a global review of ways to reduce nuisance from the beneficial weaver ant \u003cem\u003eOecophylla\u003c/em\u003e. International Journal of Agricultural Resources Governance and Ecology, 8, 484\u0026ndash;504.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWay, M. J., \u0026amp; Khoo, K. C. (1992). Role of ants in pest management. Annual Review of Entomology, 37, 479\u0026ndash;503.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWood, B. J., \u0026amp; Norman, K. (2019a). \"A review of developments in integrated pest management (IPM) of bagworm (Lepidoptera: Psychidae) infestation in oil palms in Malaysia.\" Journal of Oil Palm Research, 31(4), 529\u0026ndash;539.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWood, B. J \u0026amp; Norman, K. (2019b). \"Bagworm (Lepidoptera: Psychidae) Infestation in the centennial of the Malaysian oil palm industry\u0026mdash;A review of causes and control.\" Journal of Oil Palm Research 31(3), 364\u0026ndash;380.\u003c/span\u003e\u003c/li\u003e\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":"Asian weaver ant, quarantine bagworm, biological control, higher yield, Melaleuca alternifolia repellent","lastPublishedDoi":"10.21203/rs.3.rs-7215952/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7215952/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe invasive bagworm \u003cem\u003eMetisa plana\u003c/em\u003e Walker (Lepidoptera: Psychidae) is the dominant pest defoliator of oil palm canopies, leading to substantial leaf damage and monthly yield losses of up to 43%. Standard control methods involved trunk chemical injection (TCI) and spraying of highly toxic pesticides (such as cypermethrin) affecting non-target species. We hypothesized that the introduction of a biological control agent (BCA), the Asian weaver ant (\u003cem\u003eOecophylla smaragdina\u003c/em\u003e F.) (Hymenoptera: Formicidae), would outperform the TCI in scale and revenue consistency by controlling the bagworm population. A BCA colony was introduced with 20 brood nests translocated into four-hectare allocated experimental plots in Felda plantations, Peninsular Malaysia. To address the nuisances caused by BCA bites, we hypothesized that the essential tea tree oil (TTO) (\u003cem\u003eMelaleuca linariifolia\u003c/em\u003e var. \u003cem\u003ealternifolia\u003c/em\u003e) (Myrtales: Myrtaceae) repellency properties are a potent preventive measure. The assessment of ant-occupied palm trees shows an absence of foliar injury with higher quality fresh fruit bunches (FFB) and oil extraction rate (OER), contrasting with the high bagworm density in unoccupied, critically damaged canopies. BCA stands out as the most productive and lucrative, with more than triple the annual yield, incomes of any TCI group. Given the high correlation between yield variables and income, the polynomial regression showed accuracy in modeling BCA and TCI with minimal deviation between actual and predicted annual income. The repellent effect of TTO instantly neutralizes weaver ant aggressiveness, having an hour long lasting effect (first breakthrough report). Our findings suggest that \u003cem\u003eO. smaragdina\u003c/em\u003e is an effective alternative to pesticide control treatment of bagworms.\u003c/p\u003e","manuscriptTitle":"Oecophylla smaragdina (Hymenoptera: Formicidae): A Biological Control Agent of the Invasive Bagworms Metisa plana (Lepidoptera: Psychidae)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-05 09:25:22","doi":"10.21203/rs.3.rs-7215952/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":"c629c42c-4dda-440b-8f99-c5c5141ebefe","owner":[],"postedDate":"August 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-03T20:08:34+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-05 09:25:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7215952","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7215952","identity":"rs-7215952","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}