Abstract

Callosobruchus maculatus is the major field-to-store insect pest of stored cowpea in the tropics and sub-tropics. Despite the serious hazards to humans, livestock, and the environment, fumigants and residual insecticides are the main control methods used by farmers for cowpea protection. This study aims at evaluating the efficacy of crude extracts of botanicals (neem, water hyacinth, and soursop) in combination with solar radiation (at 0-, 48-, and 72-h) and muslin cloth for the management of C. maculatus. Fifteen grams of infested cowpea were treated with 0.3 ml of the botanicals leaf extracts, covered with either, a black, white muslin cloth, or net, and exposed to solar radiation. Adult mortality, the number of eggs laid, and the percentage of weight loss of seeds were evaluated. Results revealed 100% adult mortality on cowpea treated with botanicals, covered with black muslin, and net after 48-h of exposure. There were fewer eggs laid on seeds treated with botanicals after 48-h of exposure. It also revealed differences in weight loss of treated and untreated cowpea seeds after 48-h of exposure. The study shows that seeds treated with neem, covered with black muslin, and exposed to 72-h of solar radiation were effective in controlling C. maculatus.

Key words: Callosobruchus maculatus, botanicals, solar radiation, muslin cloth, neem, water hyacinth, soursop.