Callosobruchus maculatus (Fabricius) also known as cowpea beetle is the most important post-harvest pest of cowpea (Vigna unguiculata) which is a major source of plant protein and livestock feed for making silage and hay in Africa . Attack by C. maculatus can result in up to 100% seed damage, weight loss of up to 60% and after 6 months of storage, losses in term of perforated seed can reach 90% . C. maculatus penetrate and infest the beans by laying egg on the surface, then its larva burrow into the beans which feeds on the interior eating the tissue just under the surface; leaving a very thin layer through which it will exit when it's mature. Its infestation on seeds generally leads to reduction in vital nutrients, minerals, vitamins and other chemical constituents .