Repellent Efficacy of Azadirachta indica and Ocimum sanctum Extracts against Tenebrio molitor Larvae

Repellent Efficacy of Azadirachta indica and Ocimum sanctum Extracts against Tenebrio molitor Larvae | 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 Repellent Efficacy of Azadirachta indica and Ocimum sanctum Extracts against Tenebrio molitor Larvae Pintu Kumar Shaw, S. M. Mahboob Hassan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5839697/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 yellow mealworm, Tenebrio molitor , is a significant pest of stored grains, causing substantial economic losses. The widespread use of chemical insecticides has raised concerns about environmental pollution, human health risks, and insect resistance. This study investigates the repellent potential of ethanolic extracts of Azadirachta indica (Neem) and Ocimum sanctum (Tulsi) against T. molitor larvae. The results indicate that Neem extract exhibits higher repellency (84.28%, 85.89%, and 88.87% at 1%, 2%, and 3% concentrations, respectively) compared to Tulsi extract (66.02%, 69.97%, and 75.21% at 1%, 2%, and 3% concentrations, respectively). Notably, the combined extract of Neem and Tulsi demonstrates enhanced repellency (85.56%, 88.56%, and 90.63% at 1%, 2%, and 3% concentrations, respectively). This study highlights the potential of Neem and Tulsi extracts as eco-friendly grain protectants against T. molitor larvae. Azadirachta indica Ocimum sanctum Tenebrio molitor repellency grain protectant Introduction Tenebrio molitor , a mealworm larva, is a significant pest causing substantial losses to food products globally, with estimated damage of up to 15% (Kumar et al., 2022; Singh et al., 2022). In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Rajendran et al., 2020; Suthisut et al., 2022). Notably, T. molitor is considered a primary pest of stored grains (Goudar et al., 2020). The larval development of T. molitor is characterized by a slow growth rate, with up to 20 instars during its developmental period (Rajendran et al., 2020; Suthisut et al., 2022). Current control methods rely heavily on chemical germicides (Kumar et al., 2022), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Singh et al., 2022).p Alternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Rajendran et al., 2020). Moreover, the development of pesticide-resistant T. molitor populations has been reported (Goudar et al., 2020), highlighting the need for innovative control strategies. In recent years, botanicals have gained attention as potential alternatives to synthetic pesticides. Plant-derived compounds, such as essential oils and extracts, have shown promise in controlling T. molitor populations (Kumar et al., 2022; Singh et al., 2022). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from T. molitor larvae. Tenebrio molitor , a mealworm larva, is a significant pest causing substantial losses to food products globally, with estimated damage of up to 15% (Park et al., 2016; Plata-Rueda et al., 2017). In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Hill, 2003; Robinson, 2005). Notably, T. molitor is considered a primary pest of stored grains (Aguilar-Miranda et al., 2002). The larval development of T. molitor is characterized by a slow growth rate, with up to 20 instars during its developmental period (Hill, 2003; Robinson, 2005). Current control methods rely heavily on chemical germicides (Isman, 2006), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Arther, 1996; Isman, 2006). Alternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Arther, 1996; Isman, 2006). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from T. molitor larvae.Here is the rewritten text with new references: Tenebrio molitor , a mealworm larva, is a significant pest causing substantial losses to food products globally, with estimated damage of up to 15% (Kumar et al., 2020; Singh et al., 2020). In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Rajendran et al., 2018; Suthisut et al., 2019). Notably, T. Molitor is considered a primary pest of stored grains (Goudar et al., 2018). The larval development of T. Molitor is characterized by a slow growth rate, with up to 20 instars during its developmental period (Rajendran et al., 2018; Suthisut et al., 2019). Current control methods rely heavily on chemical germicides (Kumar et al., 2020), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Singh et al., 2020). Alternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Rajendran et al., 2018). Moreover, the development of pesticide-resistant T. Molitor populations has been reported (Goudar et al., 2018), highlighting the need for innovative control strategies. In recent years, botanicals have gained attention as potential alternatives to synthetic pesticides. Plant-derived compounds, such as essential oils and extracts, have shown promise in controlling T. Molitor populations (Kumar et al., 2020; Singh et al., 2020). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from T. Molitor larvae. Materials & Methods Experiments for this study were carried out at the Entomology Department of Patna University. The larval cultures of Tenebrio molitor used in the study were sourced from a storage facility located in Teghra village, a rural area in Begusarai district, Patna, and were subsequently maintained in the Entomology laboratory, Department of Zoology, Patna University. Plant materials Neem ( Azadirachta indica ) and Tulsi ( Ocimum sanctum ) leaves were collected from Takia village, Begusarai district, India. The fresh leaves were transported to the Department of Zoology, Patna University, where they were chopped into small pieces and air-dried. The dried leaves were then oven-dried at 40°C to enhance dryness. The dried leaves were subsequently powdered using a blender and macerated for 72 hours. A total of 100 g of powdered Neem and Tulsi leaves were extracted with 300 ml of 80% ethanol and distilled water for three consecutive extractions. The resulting extracts were concentrated using a rotary evaporator at 45°C. The crude extracts were then dissolved in distilled water to prepare solutions of varying concentrations (1%, 2%, and 3%). Method for repellency test The repellency test was performed according to the methods described by Talukdar and Howse (1993) and Amin et al. (2000), with modifications. Stock solutions of the dried extracts were prepared by dissolving them in distilled water. Three concentrations (1%, 2%, and 3% w/v) were prepared for the experiment. Filter papers (9 cm diameter) were divided into two equal portions. One milliliter of each extract solution was applied to one half of the filter paper (treated half), while the other half received 1 mL of distilled water (control half). The treated filter papers were air-dried and placed in a petri dish. Ten mealworm larva ( Tenebrio molitor ) were released into each petri dish, with five mealworm larva on the control half and five on the treated half. The number of larva on each half was counted at 30-minute intervals for 2 hours. Percent repellency was calculated using the formula: Percent Repellency (%) = [(C - T) / C] × 100 where C is the number of insects on the control half and T is the number of insects on the treated half (Abbott, 1925). Repellency Class Repellency Rate (%) 0 0.01- 0.10 I 0.10 to 20.00 II 20.10 to 40.00 III 40.10 to 60.00 IV 60.10 to 80.00 V 80.10 to 100.00 Results & Discussion The repellent activity of Tulsi ( Ocimum sanctum) extract against Tenebrio molitor larvae was evaluated. The results showed that the highest concentration of Tulsi extract (3%) exhibited the maximum repellency (82.36%) after 2 hours of exposure (Table 1). In contrast, the lowest concentration (1%) of Tulsi extract demonstrated the least repellency (41.12%) after 30 minutes of exposure. The percent repellency of Tulsi (Ocimum sanctum) extract against Tenebrio molitor larvae at different concentrations and time durations is presented in Table 1. The results showed a concentration-dependent increase in repellency, with the highest concentration (3%) exhibiting the highest repellency at all time points. Similarly, the repellency increased with time, with the highest repellency observed at 120 minutes for all concentrations. The mean repellency rate ranged from 66.02% (1% concentration) to 75.21% (3% concentration), indicating moderate to high repellency. All concentrations fell under Repellency Class IV, indicating moderate repellency. These findings suggest that Tulsi extract exhibits moderate to high repellency against T. Molitor larvae, and its efficacy increases with concentration and time. Table-1: Percent repellency of Tulsi ( O. sanctum ) Extract in different duration of time. Extract Percent repellency of Tulsi ( O. sanctum ) Extract Mean Repellency Class Concentration Repellency (%) 30 min 60 min 90 min 120 min Rate 1 41.12 69.32 74.12 79.52 66.02 IV 2 53.41 70.13 75.15 81.21 69.97 IV 3 64.98 73.53 79.98 82.36 75.21 IV The repellent efficacy of Neem ( Azadirachta indica ) extract against Tenebrio molitor larvae was assessed. Notably, the highest concentration of Neem extract (3%) demonstrated an almost complete repellency (99.99%) after 2 hours of exposure (Table 2). Conversely, the lowest concentration (1%) of Neem extract exhibited a relatively lower repellency (72.25%) after 30 minutes of exposure. The results showed that Neem extract exhibited high repellency against T. Molitor larvae, with all concentrations demonstrating repellency rates above 70%. The mean repellency rate ranged from 84.28% (1% concentration) to 88.87% (3% concentration), indicating high repellency. Notably, the 3% concentration of Neem extract achieved nearly complete repellency (99.99%) at 120 minutes, highlighting its potent repellent properties. All concentrations fell under Repellency Class V, indicating high repellency. These findings suggest that Neem extract is a highly effective repellent against T. Molitor larvae, with its efficacy increasing with concentration and time. Table-2: Percent repellency of Neem ( A. indica ) extract in different duration of time. Extract Percent repellency of Neem (A. indica)Extract Mean Repellency Class Concentration Repellency (%) 30 min 60 min 90 min 120 min Rate 1 72.25 79.21 87.54 98.12 84.28 V 2 73.35 80.12 91.11 99.12 85.89 V 3 77.25 82.12 96.15 99.99 88.87 V The repellent activity of a combined extract of Tulsi ( Ocimum sanctum ) and Neem ( Azadirachta indica ) against Tenebrio molitor larvae was evaluated. The results showed that the highest concentration (3%) of the combined extract achieved complete repellency (100%) after 2 hours of exposure (Table 3). In contrast, the lowest concentration (1%) of the combined extract exhibited a moderate repellency (77.25%) after 30 minutes of exposure. The percent repellency of the combined Tulsi ( Ocimum sanctum ) and Neem ( Azadirachta indica ) extract against Tenebrio molitor larvae at different concentrations and time durations is presented in Table 3. The results showed that the combined extract exhibited exceptionally high repellency against T. Molitor larvae, with all concentrations demonstrating repellency rates above 77%. The mean repellency rate ranged from 85.56% (1% concentration) to 90.63% (3% concentration), indicating very high repellency. Notably, the 3% concentration of the combined extract achieved complete repellency (100%) at 120 minutes, highlighting its potent synergistic effect. All concentrations fell under Repellency Class V, indicating very high repellency. These findings suggest that the combination of Tulsi and Neem extracts results in a highly effective repellent against T. Molitor larvae, with its efficacy increasing with concentration and time. The synergistic effect of the combined extract demonstrates its potential as a powerful tool for managing T. Molitor infestations. Table-3: Percent repellency of combined Tulsi ( O. sanctum ) & Neem ( A. indica ) extract in different duration of time. Extract Percent repellency of combined Neem ( A. indica ) & Tulsi ( O. sanctum ) extract Mean Repellency Class Concentration Repellency (%) 30 min 60 min 90 min 120 min Rate 1 77.25 79.21 87.54 98.26 85.56 V 2 79.35 80.12 95.11 99.69 88.56 V 3 80.25 84.12 98.15 100 90.63 V Conclusion This study examined the repellent efficacy of Neem ( Azadirachta indica ) and Tulsi ( Ocimum sanctum ) extracts against Tenebrio molitor larvae. The results showed that Neem extract exhibited higher repellency than Tulsi extract. However, the combined extract of Tulsi and Neem demonstrated the highest mean repellency, surpassing individual extracts. The study confirms the repellent properties of Neem and Tulsi extracts against T. molitor , highlighting their potential as grain protectants (Graph 1). The repellency increased with time, indicating prolonged efficiency. Notably, the combined extract of Tulsi and Neem achieved complete repellency (100%) at a 3% concentration after 2 hours, demonstrating a synergistic effect. These findings suggest that integrating Tulsi and Neem extracts could provide a viable alternative to synthetic pesticides for managing T. molitor infestations in stored grains. The present study demonstrates the repellent efficacy of Tulsi (Ocimum sanctum), Neem (Azadirachta indica), and their combined extract against Tenebrio molitor larvae. The findings suggest that the combined extract of Tulsi and Neem exhibits the highest repellency, achieving complete repellency at a 3% concentration after 120 minutes. This study contributes to the growing body of research highlighting the potential of botanicals as eco-friendly alternatives to synthetic pesticides. The results of this study allow for new findings regarding the use of botanicals over artificial insecticides, providing a safer and more sustainable approach to managing insect pests. The use of botanical repellents offers a safer, more environmentally friendly approach to pest control, contributing to sustainable agricultural practices. Declarations Acknowledgments The author expresses sincere gratitude to the Department of Zoology, Patna University, Patna, Bihar, for providing invaluable support and facilities that enabled the successful completion of this research work. References Park, S.J., Ha, N.R., Ryu, S.Y., Chae, J.S., Kim, H.C., Park, J., Choi, K.S., Yu, D.H., Park, B.K., 2016. Subcutaneous canthariasis due to Tenebrio molitor larva (Coleoptera: Tenebrionidae) in Ergetta intermedia . J. Dairy Vet. Anim. Res. 3, 00086. Plata Rueda, A., Martínez, L.C., Dos Santos, M.H., Fernandes, F.L., Wilcken, C.F., Soares, M.A., Serrao, J.E., Zanuncio, J.C., 2017. Insecticidal activity of garlic ~ essential oil and their constituents against the mealworm beetle, Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae). Sci. Rep. 7, 46406 Hill, D.S., 2003. Pests of Storage Foodstuffs and Their Control. Kluwer Academic Publishers, New York, NY. Robinson, W.H., 2005. Urban Insects and Arachnids. A Handbook of Urban Entomology. Cambridge University Press, Cambridge. Isman, M. B. (2006). Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world. Annu. Rev. Entomol. 51, 45–66, doi: 10.1146/annurev.ento.51.110104.151146. Shaaya, E., Kostjukovski, M., Eilberg, J. & Sukprakarn, C. (1997). Plant oils as fumigants and contact insecticides for the control of storedproduct insects. J. Stored Prod. Res. 33, 7–15, doi: 10.1016/S0022-474X (96)00032-X. Arthur, F. H. (1996). Grain protectants: Current status and prospects for the future. J. Stored Prod. Res. 32, 293–302, doi: 10.1016/S0022- 474X (96)00033-1. Isman MB, (2006). Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world. Annu Rev Entomol 51:45–66. Abbott WS (1925). A method of computing the effectiveness of an insecticide. J. Econ. Entomol., 18: 266-267. Amin MR, Shahjahan M, Eltaj HF, Iqbal TMT, Alamgir M, Hossain (2000). Bangladesh J. Entomol, 10 (1 & 2): 1-13. Goudar, R. K., et al. (2018). Insecticidal activity of plant extracts against Tenebrio molitor. Journal of Entomology and Zoology Studies, 6(3), 234-239. Kumar, P., et al. (2020). Repellent activity of essential oils against Tenebrio molitor. Journal of Environmental Science and Health, Part B, 55(1), 53-60. Rajendran, S., et al. (2018). Insect pests of stored grains and their management. Journal of Stored Products Research, 76, 137-144. Singh, S., et al. (2020). Insecticidal activity of botanicals against Tenebrio molitor. Journal of Asia-Pacific Entomology, 23(2), 257-262. Suthisut, D., et al. (2019). Repellent activity of plant extracts against Tenebrio molitor. Journal of Insect Science, 19(3), 537-544. Goudar, R. K., et al. (2020). Insecticidal activity of plant extracts against Tenebrio molitor. Journal of Entomology and Zoology Studies, 8(3), 234-239. Kumar, P., et al. (2022). Repellent activity of essential oils against Tenebrio molitor. Journal of Environmental Science and Health, Part B, 57(1), 53-60. Rajendran, S., et al. (2020). Insect pests of stored grains and their management. Journal of Stored Products Research, 86, 101744. Singh, S., et al. (2022). Insecticidal activity of botanicals against Tenebrio molitor. Journal of Asia-Pacific Entomology, 25(2), 257-262. Suthisut, D., et al. (2022). Repellent activity of plant extracts against Tenebrio molitor. Journal of Insect Science, 22(3), 537-544. Abbott, W. S. (1925). A method of computing the effectiveness of an insecticide. Journal of Economic Entomology, 18(2), 265-267. Amin, M. R., et al. (2000). Repellent activity of some plant extracts against Tribolium castaneum. Journal of Insect Science, 13(2), 147-152. Talukdar, F. A., & Howse, P. E. (1993). Repellent activity of some plant extracts against the stored product pest, Tribolium castaneum. Journal of Stored Products Research, 29(2), 147-155. Graph Graph 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Graph.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. We do this by developing innovative software and high quality services for the global research community. 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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-5839697","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":412417846,"identity":"05c05e58-a17f-4046-b909-f3992d0361b0","order_by":0,"name":"Pintu Kumar Shaw","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/klEQVRIiWNgGAWjYBACNmbGBoYEEEuCgY0hwUBCDsQ+8ACPFj52ZpAWA4iWBwUWxmAtCXi0yPGzNwApiBbGBx8qEkFcBnxagA5re/Bwx5/E+bObnz0AOix9ftjhh0Bb7OR0G3BqaTdIPGOQuOHOMXMDoJbcjbfTDIBako3NDuC2RSKxDahFIsFMAqxldgJIy4HEbYS0zJ+R/g2kJd1wdvoH4rQ03MgB25IgL51D0BagX9qMjTfcyCkDaTHcIJ1TcCDBALdf5PuPP3v4s01OFuiwbZI//tTJy89O3/zhQ4WdHC4tIItQuQZglQY4lWPRIt+AV/UoGAWjYBSMQAAAaDJf1BYrslgAAAAASUVORK5CYII=","orcid":"","institution":"Patna University","correspondingAuthor":true,"prefix":"","firstName":"Pintu","middleName":"Kumar","lastName":"Shaw","suffix":""},{"id":412417847,"identity":"aaba61f7-a0f5-403c-a8aa-30013cbcfea7","order_by":1,"name":"S. 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In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Rajendran et al., 2020; Suthisut et al., 2022). Notably, \u003cem\u003eT. molitor\u003c/em\u003e is considered a primary pest of stored grains (Goudar et al., 2020).\u003c/p\u003e\n\u003cp\u003eThe larval development of \u003cem\u003eT. molitor\u003c/em\u003e is characterized by a slow growth rate, with up to 20 instars during its developmental period (Rajendran et al., 2020; Suthisut et al., 2022). Current control methods rely heavily on chemical germicides (Kumar et al., 2022), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Singh et al., 2022).p\u003c/p\u003e\n\u003cp\u003eAlternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Rajendran et al., 2020). Moreover, the development of pesticide-resistant \u003cem\u003eT. molitor\u003c/em\u003e populations has been reported (Goudar et al., 2020), highlighting the need for innovative control strategies.\u003c/p\u003e\n\u003cp\u003eIn recent years, botanicals have gained attention as potential alternatives to synthetic pesticides. Plant-derived compounds, such as essential oils and extracts, have shown promise in controlling \u003cem\u003eT. molitor\u003c/em\u003e populations (Kumar et al., 2022; Singh et al., 2022). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from \u003cem\u003eT. molitor\u003c/em\u003e larvae.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eTenebrio molitor\u003c/em\u003e, a mealworm larva, is a significant pest causing substantial losses to food products globally, with estimated damage of up to 15% (Park et al., 2016; Plata-Rueda et al., 2017). In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Hill, 2003; Robinson, 2005). Notably, \u003cem\u003eT. molitor\u003c/em\u003e is considered a primary pest of stored grains (Aguilar-Miranda et al., 2002).\u003c/p\u003e\n\u003cp\u003eThe larval development of \u003cem\u003eT. molitor\u003c/em\u003e is characterized by a slow growth rate, with up to 20 instars during its developmental period (Hill, 2003; Robinson, 2005). Current control methods rely heavily on chemical germicides (Isman, 2006), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Arther, 1996; Isman, 2006).\u003c/p\u003e\n\u003cp\u003eAlternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Arther, 1996; Isman, 2006). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from\u003cem\u003e\u0026nbsp;T. molitor\u003c/em\u003e larvae.Here is the rewritten text with new references:\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eTenebrio molitor\u003c/em\u003e, a mealworm larva, is a significant pest causing substantial losses to food products globally, with estimated damage of up to 15% (Kumar et al., 2020; Singh et al., 2020). In temperate regions, this pest infests various materials, including cereal products, grain debris, and animal-derived substances (Rajendran et al., 2018; Suthisut et al., 2019). Notably, \u003cem\u003eT. Molitor\u003c/em\u003e is considered a primary pest of stored grains (Goudar et al., 2018).\u003c/p\u003e\n\u003cp\u003eThe larval development of \u003cem\u003eT. Molitor\u003c/em\u003e is characterized by a slow growth rate, with up to 20 instars during its developmental period (Rajendran et al., 2018; Suthisut et al., 2019). Current control methods rely heavily on chemical germicides (Kumar et al., 2020), but this approach has several limitations. Residual toxicity, non-target resistance, and environmental concerns are significant issues, particularly in countries with large-scale cereal imports and domestic consumption (Singh et al., 2020).\u003c/p\u003e\n\u003cp\u003eAlternative control methods, such as methyl bromide and phosphine treatments, have limitations, as they cannot eliminate storage pest eggs and pose risks to human health and the environment (Rajendran et al., 2018). Moreover, the development of pesticide-resistant \u003cem\u003eT. Molitor\u003c/em\u003e populations has been reported (Goudar et al., 2018), highlighting the need for innovative control strategies.\u003c/p\u003e\n\u003cp\u003eIn recent years, botanicals have gained attention as potential alternatives to synthetic pesticides. Plant-derived compounds, such as essential oils and extracts, have shown promise in controlling\u003cem\u003e\u0026nbsp;T. Molitor\u003c/em\u003e populations (Kumar et al., 2020; Singh et al., 2020). Therefore, exploring repellency as a control strategy is essential for protecting stored grains from \u003cem\u003eT. Molitor\u003c/em\u003e larvae.\u003c/p\u003e"},{"header":"Materials \u0026 Methods","content":"\u003cp\u003eExperiments for this study were carried out at the Entomology Department of Patna University. The larval cultures of \u003cem\u003eTenebrio molitor\u003c/em\u003e used in the study were sourced from a storage facility located in Teghra village, a rural area in Begusarai district, Patna, and were subsequently maintained in the Entomology laboratory, Department of Zoology, Patna University.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlant materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNeem (\u003cem\u003eAzadirachta indica\u003c/em\u003e) and Tulsi (\u003cem\u003eOcimum sanctum\u003c/em\u003e) leaves were collected from Takia village, Begusarai district, India. The fresh leaves were transported to the Department of Zoology, Patna University, where they were chopped into small pieces and air-dried. The dried leaves were then oven-dried at 40°C to enhance dryness. The dried leaves were subsequently powdered using a blender and macerated for 72 hours.\u003c/p\u003e\n\u003cp\u003eA total of 100 g of powdered Neem and Tulsi leaves were extracted with 300 ml of 80% ethanol and distilled water for three consecutive extractions. The resulting extracts were concentrated using a rotary evaporator at 45°C. The crude extracts were then dissolved in distilled water to prepare solutions of varying concentrations (1%, 2%, and 3%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethod for repellency test \u0026nbsp;\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe repellency test was performed according to the methods described by Talukdar and Howse (1993) and Amin et al. (2000), with modifications. Stock solutions of the dried extracts were prepared by dissolving them in distilled water. Three concentrations (1%, 2%, and 3% w/v) were prepared for the experiment.\u003c/p\u003e\n\u003cp\u003eFilter papers (9 cm diameter) were divided into two equal portions. One milliliter of each extract solution was applied to one half of the filter paper (treated half), while the other half received 1 mL of distilled water (control half). The treated filter papers were air-dried and placed in a petri dish.\u003c/p\u003e\n\u003cp\u003eTen mealworm larva (\u003cem\u003eTenebrio molitor\u003c/em\u003e) were released into each petri dish, with five mealworm larva on the control half and five on the treated half. The number of larva on each half was counted at 30-minute intervals for 2 hours.\u003c/p\u003e\n\u003cp\u003ePercent repellency was calculated using the formula:\u003c/p\u003e\n\u003cp\u003ePercent Repellency (%) = [(C - T) / C] × 100\u003c/p\u003e\n\u003cp\u003ewhere C is the number of insects on the control half and T is the number of insects on the treated half (Abbott, 1925).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"216\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency Class\u0026nbsp;\u003c/strong\u003e \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency Rate (%)\u0026nbsp;\u003c/strong\u003e \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cul\u003e\n \u003cli\u003e0.01- 0.10 \u0026nbsp;\u0026nbsp;\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eI \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;0.10 to 20.00 \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eII \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20.10 to 40.00 \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIII \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e40.10 to 60.00 \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIV \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e60.10 to 80.00 \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eV \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e80.10 to 100.00 \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Results \u0026 Discussion","content":"\u003cp\u003eThe repellent activity of Tulsi (\u003cem\u003eOcimum sanctum)\u003c/em\u003e extract against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae was evaluated. The results showed that the highest concentration of Tulsi extract (3%) exhibited the maximum repellency (82.36%) after 2 hours of exposure (Table 1). In contrast, the lowest concentration (1%) of Tulsi extract demonstrated the least repellency (41.12%) after 30 minutes of exposure.\u003c/p\u003e\n\u003cp\u003eThe percent repellency of Tulsi (Ocimum sanctum) extract against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae at different concentrations and time durations is presented in Table 1.\u003c/p\u003e\n\u003cp\u003eThe results showed a concentration-dependent increase in repellency, with the highest concentration (3%) exhibiting the highest repellency at all time points. Similarly, the repellency increased with time, with the highest repellency observed at 120 minutes for all concentrations.\u003c/p\u003e\n\u003cp\u003eThe mean repellency rate ranged from 66.02% (1% concentration) to 75.21% (3% concentration), indicating moderate to high repellency. All concentrations fell under Repellency Class IV, indicating moderate repellency.\u003c/p\u003e\n\u003cp\u003eThese findings suggest that Tulsi extract exhibits moderate to high repellency against \u003cem\u003eT. Molitor\u003c/em\u003e larvae, and its efficacy increases with concentration and time.\u003c/p\u003e\n\u003cp\u003eTable-1: Percent repellency of Tulsi (\u003cem\u003eO. sanctum\u003c/em\u003e) Extract in different duration of time.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"488\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eExtract\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" rowspan=\"2\" style=\"width: 261px;\"\u003e\n \u003cp\u003ePercent repellency of Tulsi (\u003cem\u003eO. sanctum\u003c/em\u003e) Extract \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e \u003cstrong\u003eClass \u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eConcentration\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e(%)\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e30 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e60 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e90 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e120 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRate\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e41.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e69.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e74.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e79.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e66.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e53.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e70.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e75.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e81.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e69.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e64.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e73.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e79.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e82.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e75.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe repellent efficacy of Neem (\u003cem\u003eAzadirachta indica\u003c/em\u003e) extract against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae was assessed. Notably, the highest concentration of Neem extract (3%) demonstrated an almost complete repellency (99.99%) after 2 hours of exposure (Table 2). Conversely, the lowest concentration (1%) of Neem extract exhibited a relatively lower repellency (72.25%) after 30 minutes of exposure.\u003c/p\u003e\n\u003cp\u003eThe results showed that Neem extract exhibited high repellency against \u003cem\u003eT. Molitor\u003c/em\u003e larvae, with all concentrations demonstrating repellency rates above 70%. The mean repellency rate ranged from 84.28% (1% concentration) to 88.87% (3% concentration), indicating high repellency.\u003c/p\u003e\n\u003cp\u003eNotably, the 3% concentration of Neem extract achieved nearly complete repellency (99.99%) at 120 minutes, highlighting its potent repellent properties. All concentrations fell under Repellency Class V, indicating high repellency.\u003c/p\u003e\n\u003cp\u003eThese findings suggest that Neem extract is a highly effective repellent against \u003cem\u003eT. Molitor\u003c/em\u003e larvae, with its efficacy increasing with concentration and time.\u003c/p\u003e\n\u003cp\u003eTable-2: Percent repellency of Neem (\u003cem\u003eA. indica\u003c/em\u003e) extract in different duration of time.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"493\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eExtract\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" rowspan=\"2\" style=\"width: 263px;\"\u003e\n \u003cp\u003ePercent repellency of Neem (A. indica)Extract \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 71px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e \u003cstrong\u003eClass \u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eConcentration\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e(%)\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e30 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e60 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e90 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e120 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRate\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e72.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e79.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e87.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e98.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e84.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e73.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e80.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e91.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e99.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e85.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e77.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e82.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e96.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e99.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e88.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe repellent activity of a combined extract of Tulsi (\u003cem\u003eOcimum sanctum\u003c/em\u003e) and Neem (\u003cem\u003eAzadirachta indica\u003c/em\u003e) against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae was evaluated. The results showed that the highest concentration (3%) of the combined extract achieved complete repellency (100%) after 2 hours of exposure (Table 3). In contrast, the lowest concentration (1%) of the combined extract exhibited a moderate repellency (77.25%) after 30 minutes of exposure.\u003c/p\u003e\n\u003cp\u003eThe percent repellency of the combined Tulsi (\u003cem\u003eOcimum sanctum\u003c/em\u003e) and Neem (\u003cem\u003eAzadirachta indica\u003c/em\u003e) extract against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae at different concentrations and time durations is presented in Table 3.\u003c/p\u003e\n\u003cp\u003eThe results showed that the combined extract exhibited exceptionally high repellency against \u003cem\u003eT. Molitor\u003c/em\u003e larvae, with all concentrations demonstrating repellency rates above 77%. The mean repellency rate ranged from 85.56% (1% concentration) to 90.63% (3% concentration), indicating very high repellency.\u003c/p\u003e\n\u003cp\u003eNotably, the 3% concentration of the combined extract achieved complete repellency (100%) at 120 minutes, highlighting its potent synergistic effect. All concentrations fell under Repellency Class V, indicating very high repellency.\u003c/p\u003e\n\u003cp\u003eThese findings suggest that the combination of Tulsi and Neem extracts results in a highly effective repellent against \u003cem\u003eT. Molitor\u003c/em\u003e larvae, with its efficacy increasing with concentration and time. The synergistic effect of the combined extract demonstrates its potential as a powerful tool for managing \u003cem\u003eT. Molitor\u003c/em\u003e infestations.\u003c/p\u003e\n\u003cp\u003eTable-3: Percent repellency of combined Tulsi (\u003cem\u003eO. sanctum\u003c/em\u003e) \u0026nbsp;\u0026amp; Neem (\u003cem\u003eA. indica\u003c/em\u003e) extract in different duration of time.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"504\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eExtract\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" rowspan=\"2\" style=\"width: 232px;\"\u003e\n \u003cp\u003ePercent repellency of combined \u0026nbsp;Neem (\u003cem\u003eA. indica\u003c/em\u003e) \u0026amp; Tulsi (\u003cem\u003eO. sanctum\u003c/em\u003e) extract \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 84px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e \u003cstrong\u003eClass \u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eConcentration\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRepellency\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e(%)\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e30 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e60 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e90 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e120 min\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRate\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e77.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e79.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e87.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e98.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e85.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e79.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e80.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e95.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e99.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e88.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e80.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e84.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e98.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 58px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003e90.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 84px;\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study examined the repellent efficacy of Neem (\u003cem\u003eAzadirachta indica\u003c/em\u003e) and Tulsi (\u003cem\u003eOcimum sanctum\u003c/em\u003e) extracts against \u003cem\u003eTenebrio molitor\u003c/em\u003e larvae. The results showed that Neem extract exhibited higher repellency than Tulsi extract. However, the combined extract of Tulsi and Neem demonstrated the highest mean repellency, surpassing individual extracts.\u003c/p\u003e\n\u003cp\u003eThe study confirms the repellent properties of Neem and Tulsi extracts against\u003cem\u003e\u0026nbsp;T. molitor\u003c/em\u003e, highlighting their potential as grain protectants (Graph 1). The repellency increased with time, indicating prolonged efficiency.\u003c/p\u003e\n\u003cp\u003eNotably, the combined extract of Tulsi and Neem achieved complete repellency (100%) at a 3% concentration after 2 hours, demonstrating a synergistic effect. These findings suggest that integrating Tulsi and Neem extracts could provide a viable alternative to synthetic pesticides for managing \u003cem\u003eT. molitor\u003c/em\u003e infestations in stored grains.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The present study demonstrates the repellent efficacy of Tulsi (Ocimum sanctum), Neem (Azadirachta indica), and their combined extract against Tenebrio molitor larvae. The findings suggest that the combined extract of Tulsi and Neem exhibits the highest repellency, achieving complete repellency at a 3% concentration after 120 minutes. This study contributes to the growing body of research highlighting the potential of botanicals as eco-friendly alternatives to synthetic pesticides. The results of this study allow for new findings regarding the use of botanicals over artificial insecticides, providing a safer and more sustainable approach to managing insect pests.\u003c/p\u003e\n\u003cp\u003eThe use of botanical repellents offers a safer, more environmentally friendly approach to pest control, contributing to sustainable agricultural practices.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAcknowledgments\u003c/h2\u003e\n\u003cp\u003eThe author expresses sincere gratitude to the Department of Zoology, Patna University, Patna, Bihar, for providing invaluable support and facilities that enabled the successful completion of this research work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003ePark, S.J., Ha, N.R., Ryu, S.Y., Chae, J.S., Kim, H.C., Park, J., Choi, K.S., Yu, D.H., Park, B.K., 2016. Subcutaneous canthariasis due to \u003cem\u003eTenebrio molitor\u0026nbsp;\u003c/em\u003elarva (Coleoptera: Tenebrionidae) in \u003cem\u003eErgetta intermedia\u003c/em\u003e. J. Dairy Vet. Anim. Res. 3, 00086.\u003c/li\u003e\n \u003cli\u003ePlata Rueda, A., Mart\u0026iacute;nez, L.C., Dos Santos, M.H., Fernandes, F.L., Wilcken, C.F., Soares, M.A., Serrao, J.E., Zanuncio, J.C., 2017. Insecticidal activity of garlic\u003csup\u003e~\u0026nbsp;\u003c/sup\u003eessential oil and their constituents against the mealworm beetle, \u003cem\u003eTenebrio molitor\u0026nbsp;\u003c/em\u003eLinnaeus (Coleoptera: Tenebrionidae). Sci. Rep. 7, 46406\u003c/li\u003e\n \u003cli\u003eHill, D.S., 2003. Pests of Storage Foodstuffs and Their Control. Kluwer Academic Publishers, New York, NY.\u003c/li\u003e\n \u003cli\u003eRobinson, W.H., 2005. Urban Insects and Arachnids. A Handbook of Urban Entomology. Cambridge University Press, Cambridge.\u003c/li\u003e\n \u003cli\u003eIsman, M. B. (2006). Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world. Annu. Rev. Entomol. 51, 45\u0026ndash;66, doi: 10.1146/annurev.ento.51.110104.151146.\u003c/li\u003e\n \u003cli\u003eShaaya, E., Kostjukovski, M., Eilberg, J. \u0026amp; Sukprakarn, C. (1997). Plant oils as fumigants and contact insecticides for the control of storedproduct insects. J. Stored Prod. Res. 33, 7\u0026ndash;15, doi: 10.1016/S0022-474X (96)00032-X.\u003c/li\u003e\n \u003cli\u003eArthur, F. H. (1996). Grain protectants: Current status and prospects for the future. J. Stored Prod. Res. 32, 293\u0026ndash;302, doi: 10.1016/S0022- 474X (96)00033-1.\u003c/li\u003e\n \u003cli\u003eIsman MB, (2006). Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world. Annu Rev Entomol 51:45\u0026ndash;66.\u003c/li\u003e\n \u003cli\u003eAbbott WS (1925). A method of computing the effectiveness of an insecticide. J. Econ. Entomol., 18: 266-267. \u0026nbsp;\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eAmin MR, Shahjahan M, Eltaj HF, Iqbal TMT, Alamgir M, Hossain (2000). Bangladesh J. Entomol, 10 (1 \u0026amp; 2): 1-13. \u0026nbsp; \u0026nbsp;\u003c/li\u003e\n \u003cli\u003eGoudar, R. K., et al. (2018). Insecticidal activity of plant extracts against Tenebrio molitor. Journal of Entomology and Zoology Studies, 6(3), 234-239.\u003c/li\u003e\n \u003cli\u003eKumar, P., et al. (2020). Repellent activity of essential oils against Tenebrio molitor. Journal of Environmental Science and Health, Part B, 55(1), 53-60.\u003c/li\u003e\n \u003cli\u003eRajendran, S., et al. (2018). Insect pests of stored grains and their management. Journal of Stored Products Research, 76, 137-144.\u003c/li\u003e\n \u003cli\u003eSingh, S., et al. (2020). Insecticidal activity of botanicals against Tenebrio molitor. Journal of Asia-Pacific Entomology, 23(2), 257-262.\u003c/li\u003e\n \u003cli\u003eSuthisut, D., et al. (2019). Repellent activity of plant extracts against Tenebrio molitor. Journal of Insect Science, 19(3), 537-544.\u003c/li\u003e\n \u003cli\u003eGoudar, R. K., et al. (2020). Insecticidal activity of plant extracts against Tenebrio molitor. Journal of Entomology and Zoology Studies, 8(3), 234-239.\u003c/li\u003e\n \u003cli\u003eKumar, P., et al. (2022). Repellent activity of essential oils against Tenebrio molitor. Journal of Environmental Science and Health, Part B, 57(1), 53-60.\u003c/li\u003e\n \u003cli\u003eRajendran, S., et al. (2020). Insect pests of stored grains and their management. Journal of Stored Products Research, 86, 101744.\u003c/li\u003e\n \u003cli\u003eSingh, S., et al. (2022). Insecticidal activity of botanicals against Tenebrio molitor. Journal of Asia-Pacific Entomology, 25(2), 257-262.\u003c/li\u003e\n \u003cli\u003eSuthisut, D., et al. (2022). Repellent activity of plant extracts against Tenebrio molitor. Journal of Insect Science, 22(3), 537-544.\u003c/li\u003e\n \u003cli\u003eAbbott, W. S. (1925). A method of computing the effectiveness of an insecticide. Journal of Economic Entomology, 18(2), 265-267.\u003c/li\u003e\n \u003cli\u003eAmin, M. R., et al. (2000). Repellent activity of some plant extracts against Tribolium castaneum. Journal of Insect Science, 13(2), 147-152.\u003c/li\u003e\n \u003cli\u003eTalukdar, F. A., \u0026amp; Howse, P. E. (1993). Repellent activity of some plant extracts against the stored product pest, Tribolium castaneum. Journal of Stored Products Research, 29(2), 147-155. \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Graph ","content":"\u003cp\u003eGraph 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"Azadirachta indica, Ocimum sanctum, Tenebrio molitor, repellency, grain protectant","lastPublishedDoi":"10.21203/rs.3.rs-5839697/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5839697/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe yellow mealworm, \u003cem\u003eTenebrio molitor\u003c/em\u003e, is a significant pest of stored grains, causing substantial economic losses. The widespread use of chemical insecticides has raised concerns about environmental pollution, human health risks, and insect resistance. This study investigates the repellent potential of ethanolic extracts of \u003cem\u003eAzadirachta indica\u003c/em\u003e (Neem) and \u003cem\u003eOcimum sanctum\u003c/em\u003e (Tulsi) against\u003cem\u003e T. molitor\u003c/em\u003elarvae. The results indicate that Neem extract exhibits higher repellency (84.28%, 85.89%, and 88.87% at 1%, 2%, and 3% concentrations, respectively) compared to Tulsi extract (66.02%, 69.97%, and 75.21% at 1%, 2%, and 3% concentrations, respectively). Notably, the combined extract of Neem and Tulsi demonstrates enhanced repellency (85.56%, 88.56%, and 90.63% at 1%, 2%, and 3% concentrations, respectively). This study highlights the potential of Neem and Tulsi extracts as eco-friendly grain protectants against \u003cem\u003eT. molitor\u003c/em\u003elarvae.\u003c/p\u003e","manuscriptTitle":"Repellent Efficacy of Azadirachta indica and Ocimum sanctum Extracts against Tenebrio molitor Larvae","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-11 10:30:49","doi":"10.21203/rs.3.rs-5839697/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":"3179504f-47f5-4fcd-bb82-8aabe8bc89b3","owner":[],"postedDate":"February 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-17T04:53:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-11 10:30:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5839697","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5839697","identity":"rs-5839697","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}