The Generic Status of Cowpea Weevil from Agroecological Zones of Ghana: Has Callosobruchus Maculatus (Coleoptera: Bruchidae) from the Two Agroecological Zones Evolved into Different Species?

Callosobruchus maculatus is the most important cowpea storage pest in Ghana. Total loss can occur if the grain is stored without adequate protection for about six months. Even when resistant varieties are developed, ecotypes of C. maculatus easily evolve to overcome the resistance as this resistance is di-genically controlled. This book, based on studies conducted in Ghana, investigates possible differences in the cowpea weevil from two agroecological zones in Ghana. C. maculatus from the Coastal savanna and the Forest savanna transition zones were studied to find out whether changes have occurred in their generic status. The studies were conducted at the Crop and Soil Sciences Department, KNUST, Ghana under laboratory conditions of 27°C - 35°C temperature range and 65%-99% relative humidity. Parents from the same location were mated and reciprocal crosses were also made. Parameters measured showed differences in adult size, developmental period, longevity and sex ratio. Results indicate that when the two original populations stay apart for some more time, subspecies will develop. This book will be useful to agricultural scientists interested in insect pests of cowpea.