INSECTICIDAL EFFICACY OF THREE NON-VOLATILE EDIBLE OILS ON CALLOSOURUCHUS MACULA TUS (V.) INFESTING STORED COWPEA SEEDS LN LAF1A, NIGERIA.

he comparative effects of three non-volatile edible plant oil extracted by traditional kneading method from the seeds o f beeniseed (Sesame indicum), horseradish (Moringa oleifera) and olive fruits (Olea europaea) were evaluated on cowpea seeds (Tigna unguiculata) as pre- and post-oviposition treatment against the development o f cowpea bruchid. Callosobritchus maculatus under prevailing storage conditions (25-29"C and 41-53% r.h.) in l.afa, Nigeria. Pre- and post-oviposition applications o f the oils at rates o f50, 100, ISO. 200 and 250 mg'lO g seed were effective in reducing the development of adult C. maculatus when compared with the untreated check. Oil extracted front henniseed caused 100% mortalities o f eggs at all the dosage levels in both pre- and post-oviposition treatments. In both pre and post-oviposition applications, the dosages o f 200 and 250 mg 10 g seed completely suppressed the development of adult progeny in the first generation. All the oils u w able to protect cowpea seeds significantly for three months when compared to the untreated check.