The cowpea weevil derives its name from the bean that it feeds upon. Its attacks are not limited to cowpeas, however. Cowpea weevils will consume all manner of beans, dried or recently harvested.
Cowpea weevils are relatively small, about an eighth of an inch long, with a dull-colored, teardrop-shaped body and red or white markings. They are not true weevils, since they do not possess a snout-shaped head. Cowpea weevils feed on stored beans and peas. They spend their larval stages inside the beans, consuming it for food.
Adult cowpea weevils are usually found on flowers in early spring. They lay their eggs and when the eggs hatch, the larvae dig their way in to live inside the cowpea. They feed on the cowpea, taking from 2 weeks to 6 months to emerge. The adults prefer dried cowpeas and will remain and breed continuously in areas where the dried cowpeas are stored. Cowpea weevils are in a group of pests that are referred to as stored product pests, due to their propensity to feed on dried peas and beans.
Cowpea weevils thrive in high heat and humidity. They are primarily found in the Southern regions of the US. Harvesters, planters or storage areas in bean fields can become infested with cowpea weevils. Cowpea weevils will infest areas so heavily that newly hatched weevils must leave the infested area to find beans to lay their eggs upon.
To help manage cowpea weevils, remove broken sacks or spilled bean seeds from storage areas and keep dried beans in sealed containers. Cowpea weevils do not carry diseases, but with a large infestation, crops can devalue greatly. The signs of an infestation will include a large number of cowpea weevils flying around a site. Look also for beans that have holes in them as a sign of damage and infestation.