Evaluation of the bio-insecticidal effects of the main fatty acids of olive oil on Callosobruchus maculatus F. (Coleoptera-Bruchidae) in cowpea (Vigna unguiculata (L.))
Résumé
In this study the biological impact of olive oil on Callosobruchus maculatus F. (Coleoptera: Bruchidae) and its development in stored grain was evaluated. The investigation was intended to validate the effectiveness of a traditional method of protecting vegetable crops as compared with the use of pesticides whose disadvantages are well known. Seed treatments were carried out by coating Vigna unguiculata (L.) with olive oil, and with each of the major fatty acids contained in olive oil (oleic, linoleic, stearic, and palmitic) and a mixture of these compounds. The biological parameters studied to evaluate the effects of these different treatments are longevity, fecundity, and amount of hatched eggs and emerged adults of the cowpea weevil. With the exception of the treatments with stearic acid and palmitic acid, the treatments revealed statistically significant insecticidal effects against the cowpea beetle. Moreover, it is shown that such insecticidal treatments do not negatively impact the germination ability of cowpea seeds.