Abstract

The role of seed coat thickness in the resistance/susceptibility of V. unguiculata (black-eyed beans, Cultivar: Black-eyed peas) against infestation by the bruchid beetle C. maculatus (F.), was investigated. Decoated V. unguiculata beans were individually coated in one to four of previously removed seed coats or one layer of Phaseolus vulgaris (Red Kidney Beans-British Type) seed coat, before being offered to non-virgin C. maculatus females to oviposit on. Following incubation for several weeks, the total adult emergence was then used to determine egg-adult survival and the seed coat thickness for both types of beans was measured. The seed coat of P. vulgaris was approximately three times thicker than that of V. unguiculata. The survival of larvae in the four coats V. unguiculata treatment was similar to that of P. vulgaris seed coat, which showed the high correlation of seed coat thickness with V. unguiculata beans resistance to C. maculatus.