Identification

Common weevils found in beans are the cowpea weevil, Callosobruchus maculatus; broad bean weevil, Bruchus rufimanus; and the bean weevil, Acanthoscelides obtectus. Adult weevils found in beans are relatively small beetles, 0.13 - 0.2 inch in length, somewhat teardrop or triangular in shape, and dull-colored with white, reddish, or black markings.

Life Cycle

Weevil eggs may be glued to the bean or the pod (cowpea weevil), glued to green pods (broad bean weevil), or laid loosely among beans or through cracks in the pods (bean weevil). The larval and pupal stages are spent inside the bean. Adults emerge from beans through a round hole in the bean seed coat. Bean weevil infestations can start in the garden or in trash beans. Damage is a combination of feeding and contamination.

Damage

Damage may occur in the garden or in storage. Weevil larvae feed within the bean pod and consume nearly the entire bean contents.

Solutions

Be sure seeds are free of weevils before planting. Remove and destroy bean plants immediately after harvest. Treatment with insecticides is not recommended.