Bioinsecticidal Activities of Azadirachta indica A. Juss (Meliaceae) Seed Oil Extracts on Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae) on Stored Maize
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Abstract
The preservation of stored grains against weevil infestations is critical for ensuring food security and minimizing post-harvest losses in Nigeria, where insect pests remain a major constraint to effective grain storage. This study evaluates the efficacy of seed extracts of Azadirachta indica in controlling Sitophilus zeamais. Seeds were extracted using five solvents—methanol, ethanol, acetone, petroleum ether, and n-hexane—and the resulting oils were tested for their effects on insect mortality, oviposition, adult emergence, grain damage, and long-term storage viability. Results indicate that ethanol extract was the most effective, inducing 100% mortality within 96 hours of exposure, followed by n-hexane (88.25%), petroleum ether (85.75%), methanol (82.25%), and acetone (76.15%). Extracts also significantly reduced oviposition and adult emergence, with complete suppression observed in ethanol-, petroleum ether-, and n-hexane-treated grains. These treatments also fully prevented grain damage and weight loss for three months, while methanol and acetone extracts allowed limited damage (9.19% and 8.18%, respectively). Germination tests showed high viability (95.25–98.25%) across all treatments, with the lowest germination recorded in petroleum ether extract (95.25%). The findings suggest that A. indica seed extracts are highly effective in managing S. zeamais infestations and represent a viable alternative to synthetic insecticides for safe and sustainable grain storage.

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References
Adedire, C, Akinkurolere, R.O and Obembe, O.M. (2011). Efficacy of cashew kernel extracts in the control of the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae), Archives of Phytopathology and Plant Protection, DOI:10.1080/03235408.2011.598259.
Adesina, J. M. (2013). Insecticidal potential of Mormordica charantia (L.) leaves powder against maize weevil, Sitophilus zeamais (Mots) (Coleoptera: Curculionidae) infestation. International Journal of Biosciences, 3: 28-38.
Adiaha, M. S., 2017. Economics of maize (Zea mays L.) Production in Nigeria and Maize Traditional Utilization. International Journal of Scientific World, 5 (2): 106-109.
Ahmed, D.M., Mohsen, A.E.A.M., El-Deeb, M.A., Alkhedaide, A., El-Tahan, A.M., Metwally, E.S.M. (2022). The larvicidal effect of neemazal T/S, clove oil and ginger oil on tomato leafminer, Tuta absoluta compared to coragen. Saudi Journal of Biological Sciences, 29(3): 1447-1455.
Akinbuluma, D., and Ewete, K.F. (2014). “Comparative efficacy of extracts from Azadirachta indica, Piper guineense and pirimiphos-methyl against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) in stored maize, Journal of Biology, Agriculture and Healthcare, 4 (27): 327–335.
Akinkurolere, R.O., Adedire, C.O., Odeyemi, O.O. (2006). Laboratory evaluation of the toxic properties of forest Anchomanes, Anchomanes difformis against pulse beetles Callosobruchus maculatus (Coleoptera: Bruchidae). Insect Sci., 13:25–29.
Alonso, A., and Avila, N., (2011). Comparison of seven methods for stored cereal losses to insects for their application in rural conditions. Journal of Stored Products Research, 4: 82-87.
Ayvaz, A., Sagdic, O., Karaborklu, S., Ozturk, I. (2010). Insecticidal activity of the essential oils from different plants against three stored-product insects. Journal of Insect Science 10:21.
Koul, O. (2008). Phytochemicals and Insect Control: An Anti-feedant Approach. Critical Reviews in Plant Sciences, 27(1): 1–24.
Barik, N., Singh, D., and Prajapati, S. K., (2021). Efficacy of neem (Azadirachta indica) oil against Sitophilus oryzae infestation in stored wheat. Journal of Pharmacognosy and Phytochemistry, 10(6): 192-195
Birhanu, H., and G, Emana, (2018). “Efcacy of solvent extracts of Calpurnia aurea (Ait.) Benth and Milletia ferruginea (Hochest) Baker leaves against maize weevils, Sitophilus zeamais (Motsch.) of stored maize in Ethiopia, Journal of Stored Products and Postharvest Research, 9: 27–35
Campolo, O,G., Giunti, A., Russo, V., Palmeri, Zappala, L. (2018). Essential oils in stored product insect pest control. Journal of Food Quality, 1–18.
Compact Oxford English Dictionary (COED) (2013). Neem. Oxford University Press. (3): 679.
Fatope, M.O., Nuhu, A.M., Mann, A., Takeda, Y. (1995). Cowpea weevil bioassay: a simple prescreen for plants with grain protectant effect. Int J Pest Mgmt., 41(2): 84–86.
Frankenfeld, I.C. (1948). Staining methods for detecting weevil infestation in grain. U.S. Department of Agriculture, Bureau of Entomological Plant Quarantine E.T. 256.
Ileke, K.D., Ogungbite, O.C., Olayinka- Olagunju, J.O. (2014). Powders and extracts of Syzgium aromaticum and Anarcadium occidentale as entomocides against the infestation of Sitophilus oryzae (L.) (Coleoptera: curculinionidae) on stored sorghum grains. Afr. Crop Sci. J., 22(4): 267–273.
Lengai, G.M.W., Muthomi, J.W., Mbega, E.R. (2019). Phytochemical activity and role of botanical pesticides in pest management for sustainable agricultural crop production. Scientific African, e00239.
Listman, G.M., Guzmán, C., Palacios-Rojas, N., Wolfgang H., Pfeiffer F.S.V. and Velu, G. (2019). Improving Nutrition through Bio-fortification: Pre-harvest and Post-harvest Technologies. International Maize and Wheat Improvement Center, (CIMMYT), Carretera México-Veracruz, Km 45, El Batán, Texcoco, México, 56237.
Mobolanle, D. A., Yeye E.O.E., Ewete, F.K. (2015). Qualitative Phytochemical screening of Acalypha fimbriata, and its methanol extract as protectant against Sitophilus zeamais (Coleoptera: Curculionidae) on stored maize. Journal of Natural Science Research, 5(6): 136-141.
Muzemu, S., Chitamba, J., Goto, S. (2013). Screening of Stored Maize (Zea mays L.) Varieties Grain for Tolerance against Maize Weevil, Sitophilus zeamais (Motsch.). International Journal of Plant Research, 3: 17-22.
Mwamburi, L.A. (2022). Role of Plant Essential Oils in Pest Management. In: New and Future Development in Biopesticide Research: Biotechnological Exploration. Singapore: Springer Nature Singapore pp. 157-185.
Ngegba, P.M., Cui, G., Khalid, M.Z., Zhong, G. (2022). Use of Botanical Pesticides in Agriculture as an Alternative to Synthetic Pesticides. Agriculture 12(5): 2-24
Obembe, O.M., Olanipekun, M.K., and Ojo, D.O. (2023). Evaluation of the insecticidal potential of Leaf oil Extracts of Acalypha wilkesiana (Muel.) Arg. against the Cowpea Weevils, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae, Bruchidae). Scholar Academic Journal Biosciences, 11(3): 1-7
Ojo, D.O., Ogunleye, R.F. (2013). Comparative effectiveness of the powders of some underutilized botanicals for the control of Callosobruchus maculatus (Coleoptera: bruchidae), J. Plant Dis. Prot. 120(5): 227–232.
Ojo, J.A., Omoloye, A. A. (2012). Rearing the maize weevil, Sitophilus zeamais, on an artificial maize cassava diet, Journal of Insect Science, 12(69): 1-8.
Okolo, E. T., and Iledun, O.C. (2019). Insecticidal effect of neem (Azadirachta indica) extracts obtained from leaves and seeds on pests of cowpea (Vigna unguiculata). Sumerianz Journal of Agriculture and veterinary sciences (4): 20-28.
Olaniyan, A. B., (2015). Maize: Panacea for hunger in Nigeria. African Journal of Plant Science, 9(3): 155-174.
Panchal, M., Shah, B., Murti, K. and Shah, M. (2011). Phytochemical investigation and antidiabetic activity studies of Moringa oleifera roots. Research Journal of Pharmacology and Pharmacodynamics, 3(5): 268-277.
Regnault-Roger, C., Vincent, C., Arnason, J.T. (2012). Essential oils in insect control: low-risk products in a high-stakes world. Annual review of entomology, 57: 405-424.
Singh, P., Singh, A. K., and Singh, R. K. (2021). Efficacy of neem, Azadirachta indica oil against Sitophilus oryzae (L.) infestation in stored maize. International Journal of Agriculture, Environment and Biotechnology, 14(3): 693-697.
Smith, A. L., El-Wakeil, N. E., Amer, M. A., and MeyerRochow, V. B., (2020). Insecticidal effects of neem (Azadirachta indica) on the maize weevil (Sitophilus zeamais). Frontiers in Environmental Science, 8, 29.
Srivastava, S., and Srivastava, A. K. (2013). Production of the Biopesticide Azadirachtin by Hairy Root Cultivation of Azadirachta indica in Liquid-Phase Bioreactors. Applied Biochemistry and Biotechnology. 171(6): 1351-1361.
Tembo, Y., Mkindi, A.G., Mkenda, P.A., Mpumi, N., Mwanauta, R., Stevenson, P.C., Ndakidemi, P.A., and Belmain. S.R. (2018). Pesticidal Plant extracts improve yield and reduce insect pests on legume crops without harming beneficial arthropods. Frontiers in Plant Science, 9:14-25.
Tripathi, S., Prakash, R., and Srivastava, P. C. (2022). Evaluation of neem-based biopesticides against Sitophilus oryzae (L.) in stored maize. Journal of Pharmacognosy and Phytochemistry, 11(3): 700-705.
Trivedi, A., Nayak, N., Kumar, J. (2017). Fumigant toxicity study of different essential oils against stored grain pest Callosobruchus chinensis. Journal of Pharmacognosy and Phytochemistry, 6(4): 1708-1711.
Udebuani, A. C., Abara, P. C., Obasi, K. O. and Okuh, S. U. (2015). Studies on the insecticidal properties of Chromolaena odorata (Asteraceae) against adult stage of Periplaneta Americana Journal of Entomology and Zoology Studies, 3(1): 318-321.














