Varietal resistance and intraspecific competition in the cowpea weevils Callosobruchus maculatus and C. chinensis (Coleoptera: Bruchidae).
Abstract
When Callosobruchus maculatus (F.) was provided with the seeds of several varieties of cowpea (Vigna unguiculata) in the laboratory in the UK and was at different larval densities, the percentage of adults emerging differed with the variety and larval density, but there was no evidence of interaction between the 2 factors. For both C. maculatus and C. chinensis (L.), there was a significant reduction in larval mortality at lower densities, except that, at the lowest density, mortality increased sharply for both species of beetle (inverse density-dependence). The influence on mortality was greater for C. maculatus than for C. chinensis.