Abstract: Citrullus colocynthis (L.) Schrad seeds generally called Egusi melon are widely eaten in Nigeria, but its uses in post-harvest crop protection have not been exploited. The effects of the edible oil of C. colocynthis seeds on Callosobruchus maculatus (F.) were assessed on adult mortality, oviposition, F1 progeny emergence, cowpea seed damage and seed germinability in the laboratory. Results indicated that the oil showed some lethal effects on treated insects at above 50% mortality and very high reduction in oviposition at increased concentrations. Seeds treated with the oil showed significant (P<0.05) reduction in the number of progeny of C. maculatus. There was no observable feeding damage on seeds treated with the highest concentration of the oil applied. In addition, the oil has no adverse effect on seed viability. The present studies indicate that the application of the oil show promise in post-harvest protection of cowpea seeds.

Keywords: Citrullus colocynthis seed oil, cowpea seed protection; Callosobruchus maculatus.