Bruchid infestation of cowpea varieties in the field.
Cowpea (Vigna unguiculata) is one of the most widely grown leguminous crops in Africa. In Kenya it occupies over 66 000 ha. At Mtwapa from 1979 to 1981, 5 bruchid species infesting cowpea varieties in the field were identified. These were Callosobruchus rhodesianus, C. phaseoli, C. chinensis, Bruchidius atrolineatus and C. analis, in order of decreasing abundance. Over 50% of the bruchids found were C. rhodesianus while Zabrotes spp. and C. maculatus were never encountered. There were more bruchid infestations during the short rainy season than in the long rainy season.