DOI: 10.36347/sajb.2016.v04i03.017

Pages: 258-263

Interspecific competition was investigated in bruchids (Coleoptera: Chrysomelidae) major pests of stored Bambara groundnut (BGN), during eggs laying process. Field observations carried out for 2 years revealed that 2 bruchids Callosobruchus maculatus (Fab.) and Callosobruchus subinnotatus (Pic.) are major pests of BGN; C. maculatus is more prolific and dominant in the Sudano Sahelian landscape whereas C. subinnotatus is the major pest in the Sudano Guinean area. Intraspecific competition affects the amount and the fertility of eggs laid. C. maculatus laid more eggs in presence of C. subinnotatus than it does alone. Moreover, C. subinnotatus added very few barren eggs on seeds upon which C. maculatus oviposited previously. Allelo chemicals involved in this phenomenon are to be described.