Efficacy of Selected Seed Oils against the Fecundity of Callosobbruchus Maculatus(F.) (Coleoptera: Bruchidae)

Efficacy of admixing traditionally extracted oils from five different plants to two varieties of cowpea (Vigna unguiculata L. WaIp)seeds; Sokoto local and Kananado during storage, against the fecundity of cowpea bruchid (Callosobruchus maculatus F.) was investigated under ambient laboratory conditions. Oils from seeds of neem, cotton, groundnut, castor and desert dates were extractedand ten oil mixtures pair- wise were formulated in five dosages (0.5, 1.0, 2.0, 3.0 and 4.0ml). Each was used to treat 50g seed of the cow peas, and then infested with 10 pairs of adults’ C. maculatus in petri-dishes alongside untreated seeds. Fecundity of the females was determined 14 days post infestation by calculating number of eggs laid per female in each petri-dish. Effect of the oils on females’fecundity was observed to be indirectly proportional to the dosage used for treating both cow peas. Neem kernel oil applied as straightand in mixtures proved to be more efficacious than the remaining oils. Significant differences (p>0.05) for reduced fecundity on
treated and untreated seeds were observed. Comparatively, fewer eggs per female were laid on Kananado, implying that in addition tothe effect of oils this variety is resistant to bruchid attack.