Intraspecific competition in the bean weevils Callosobruchus maculatus and Callosobruchus rhodesianus (Coleoptera: Bruchidae).
Abstract
Effects of intraspecific competition in Callosobruchus maculatus and C. rhodesianus on cowpeas were studied in the laboratory in order to predict whether density-dependant effects might limit the pest potential of C. rhodesianus in stored legumes. Development rate and sex ratio were not affected by larval density in either species. Increased larval density reduced survivorship and emergence weight in both species. Increased adult density reduced the number of eggs laid per female and the hatchability of eggs in C. maculatus but not in C. rhodesianus. The reproductive curves of both species were similar. It is concluded that it is arguable that intraspecific competition would not limit the potential of C. rhodesianus to become a major pest of stored legumes.