Bioactivity of the Leaf and Stem Bark Extracts of Siam Weed (Chromolaena odorata) L. on Cowpea seed pest, Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae) in Storage

Abstract: The use of botanical insecticides as potent alternatives in the control of insect pests of agricultural products have been established. Chromolaena odorata is a plant which has both medicinal and insecticidal properties. The leaves and stem barks of this plant were extracted using different solvents namely, methanol, ethanol, water, acetone, pet-ether and n-hexane. The different extracts were evaluated on C. maculatus adults for their mortality, oviposition and adult emergence. The effect of the extracts on seed viability was also investigated. The leaves and stem barks were also analysed to know the phytochemicals present. The results obtained showed that the steam distillate of leaves and stem barks of C. odorata were most toxic to C. maculatus for causing 100 % and 95.75 % respectively within 96 h of exposure. The leaf and the stem bark extracts of the plant effectively reduced oviposition in C. maculatus. The percentage adult emergence in the untreated (control) cowpea seeds was significantly higher than emergence in the treated seeds. The Percentage germination of all treated seeds by the 7th day was generally high. The Phytochemical analysis of the leaf of C. odorata showed that Tannins, Terpenoid were present in large quantity. While alkaloid, flavonoids, saponins, cardiac glycosides and steroid were present. Phytochemical analysis of the stem bark extract of C. odorata showed that alkaloid, tannins, flavonoids, saponins, terpenoid, cardiac glycosides and steroids were present. The results obtained from this study revealed that the extract of C. odorata are effective in controlling cowpea storage weevils, C. maculatus and could serve as an alternative to synthetic insecticides for the protection of stored cowpeas against C. maculatus. Keywords: Chromolaena odorata, Callosobruchus maculatus Oviposition, Adult emergence, viability and phytochemicals. Title: Bioactivity of the Leaf and Stem Bark Extracts of Siam Weed (Chromolaena odorata) L. on Cowpea seed pest, Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae) in Storage Author: Obembe Olusola Michael, Okunola Tunde Timothy, Ayeyi Olayinka Mercy International Journal of Life Sciences Research ISSN 2348-313X (Print), ISSN 2348-3148 (online) Vol. 12, Issue 4, October 2024 - December 2024 Page No: 76-85 Research Publish Journals Website: www.researchpublish.com Published Date: 31-December-2024 DOI: https://doi.org/10.5281/zenodo.14580912 Paper Download Link (Source) https://www.researchpublish.com/papers/bioactivity-of-the-leaf-and-stem-bark-extracts-of-siam-weed-chromolaena-odorata-l-on-cowpea-seed-pest-callosobruchus-maculatus-fabricius-coleoptera-bruchidae-in-storage