Impact of sublethal doses of Piper guineense (Schum and Thonn) on the biological parameters of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) reared on different cowpea varieties

•The response of C. maculatus to P. guineense was influenced by the variety of the stock culture.•Fecundity, hatchability, and survival differed among the exposed varietal populations.•Oviposition and hatchability index of C. maculatus postively correlated with the cowpea varieties.•Varietal difference, and not just exposure to sublethal doses of P. guineense, explained observed response.•Thus, white cowpea seeds predisposed C. maculatus to sublethal effects of P. guineense  than colored seeds.