Facts, Identification, & Control
Callosobruchus maculatus (Fabricius)
What Do They Look Like?
- Size: Cowpea weevils are about 2 to 5.4 mm long.
- Color: They are brownish in color with black markings on their wing covers. Their wings do not cover them completely, so black markings are visible on the end of their abdomens.
How Did I Get Cowpea Weevils?
Infestations in homes can come from beans grown in the garden or from packaged beans from a store. Cowpea weevils develop while hidden inside dry beans and other goods in pantries.
How Serious Are Cowpea Weevils?
Cowpea weevil larvae cause damage by contaminating and destroying food. These pests do not live for long periods, but are adept at distributing their eggs and evading capture, which means infestations are often tough to control.
They eat these goods from within, making infested products hard to detect. Infestations spread quickly once these insects escape from stored goods.
Signs of Infestation
These adult weevils can be seen flying towards windows. Beans or grains with holes are a major sign of a cowpea weevil infestation.
How Do I Get Rid of Cowpea Weevils?
What You Can Do
Preventive measures to help control cowpea weevils include:
- Discarding infested items
- Sealing containers
- Vacuuming pantries
What Orkin Does
Your local Orkin technician is trained to help manage cowpea weevils and similar pests. Since every building or home is different, your Orkin technician will design a unique program for your situation.
Orkin can provide the right solution to keep cowpea weevils in their place and out of your home or business.
Behavior, Diet, & Habits
Cowpea weevils, Callosobruchus maculatus (Fabricius), are pests of stored beans. As their name suggests, they infest cowpeas.
They are a member of a group of beetles called Bruchids. Other Bruchids, including the pea weevil, Bruchus pisorum (Linnaeus) and the bean weevil, Acanthoscelides obtectus (Say) are also pests of stored beans.
Cowpea weevils are known as “internal feeders.” If beans are stored in a warm, humid place, life cycles can be completed in as little as three weeks.
Female cowpea weevils deposit eggs on developing pods or on the surface of stored beans. When larva hatches from eggs, they burrow deep into a bean.
Larvae bore into these beans and begin to eat. One seed can support more than one larva at the same time. They stay inside these beans until they emerge as adults.
When they tunnel out of seeds as adults, these pests are very fast fliers and fast runners. Once emerged, female moths fly out and deposit eggs of their own on the same beans where they were developed.