Callosobruchus maculatus is a common pest of cowpea. Cowpea is a type of bean that is widely grown and consumed in many parts of the world. Callosobruchus maculatus is a tiny beetle that feeds on the seeds of the cowpea plant. This insect can cause serious damage to the crop, reducing the yield and quality of the beans. The beetle lays its eggs on the surface of the cowpea seeds, and when the eggs hatch, the larvae burrow into the seed and start feeding on it. This feeding can damage the seed and make it unviable, reducing the yield of the crop.