GC-MS-MS profiling and toxicity of ethyl acetate extracts of some botanicals against rice weevil, Sitophilus oryzae (L.) in stored maize Anandhabhairavi N.1,*, Shanthi M.2, Vellaikumar S.3, Arivarasan S.4, Jayapal P.5 1Department of Agricultural Entomology, School of Agriculture, VELS Institute of Science, Technology & Advanced Studies (VISTAS), Velan Nagar, Chennai-600 117 (Tamil Nadu), India 2Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore-641 003 (Tamil Nadu), India 3Department of Biotechnology, Agricultural College and Research Institute (AC&RI), Tamil Nadu Agricultural University (TNAU), Madurai-625 104 (Tamil Nadu), India 4Department of Agricultural Economics, School of Agriculture, VELS Institute of Science, Technology & Advanced Studies (VISTAS), Velan Nagar, Chennai-600 117 (Tamil Nadu), India 5Department of Animal Genetics & Breeding, Veterinary College and Research Institute, Namakkal-637 001, (Tamil Nadu), India *(e-mail: anandhabhairavi03@gmail.com)
Online published on 2 August, 2023. Abstract Ethyl acetate extracts of certain botanicals were evaluated in the laboratory for their contact and oral toxicity at 5% concentration against Sitophilus oryzae L. at Natural Pesticide Laboratory, Department of Agricultural Entomology, Agricultural College and Research Institute, Madurai, Tamil Nadu during 2019-21. The result revealed that all the botanicals were effective against S. oryzae compared to the control. Considering the contact toxicity, 5% ethyl acetate extract of Mentha spicata (86.67%) performed better 72 h after treatment. Vitex negundo and Ocimum sanctum caused (83.33%) mortality 72 h after treatment concerning oral toxicity. Mentha spicata caused 93.33% mortality after 15 days of treatment, whereas Vitex negundo, Ocimum sanctum and Tagetes erecta leaf caused 90.00% mortality, which was statistically at par with Mentha spicata. GC-MS-MS study revealed the presence of carvone (38.27%) at the retention time of 7.644, Hexadecanoic acid (2.13%) at the retention time of 27.600, Isopulegol (1.41%) at the retention time of 27.290 and phytochemicals with insecticidal potential in Mentha spicata.Whereas in Ocimum sanctum, Eugenol (59.72%) was the major compound at the retention time of 9.9. Hence, it was concluded that among the tested ethyl acetate extracts, Mentha spicata at 5% was the most effective as a contact and oral toxicant against S. oryzae in stored maize, which possesses the bioactive principle of carvone and it can be developed as an ecofriendly botanical formulation. Top Keywords Botanicals, Carvone, Ethyl acetate, Mentha spicata, Sitophilus oryzae, Toxicity. Top |