INSECTICIDAL ACTIVITY OF PIPER GUINEENSE (SCHUMACH AND THONN) SEED OIL AGAINST CALLOSOBRUCHUS MACULATUS (F.) (COLEOPTERA: CHRYSOMELIDAE) IN STORED COWPEA SEEDS

Abstract

Post-harvest losses due to insect pest infestation in storage constitute a challenge to sustainable food security and economic losses to farmers throughout the world. Use of synthetic chemicals have been the most effective means of reducing losses in storage. Unfortunately, these toxicants have adverse effects in humans and the environment. There is renewed search for safer plant products as alternatives. In this study, we assessed the potential use of Piper guineense seed oil in the control of cowpea bruchid, Callosobruchus maculatus (F.) infestation on stored cowpea seeds. Adult mortality, oviposition rate, F1 progeny emergence, cowpea seed damage and seed germinability were the indices considered in the assessment under laboratory conditions. The setup of the experiment was completely randomized design (CRD). Statistical analysis of the data was by analysis of variance (ANOVA). Adult C. maculatus mortality was dose-dependent with higher dosages inducing 100% mortality. The number of eggs laid on the treated seeds were significantly (P<0.001) reduced. Progeny emergence and feeding damage were completely inhibited at higher dosages. The seed oil has no adverse effect on cowpea seed viability. The results indicated that P. guineense seed oil has protectant potential against insect pest damage in storage and a good alternative to synthetic insecticides in the control of insect pest of stored products.