Bean and Cowpea Weevils

Acanthoscelides obtectus; Callosobruchus maculatus

Bean Weevil

Bean weevil (Clemson University, Bugwood.org)

Cowpea Weevil

Cowpea weevil (Ryan Davis, Utah State University Extension)

Sweet Potato Damage

Cowpea weevil damage to sweet potato (B. Merle Shepard, Clemson University, Bugwood.org)

Identification

bean weevil:

  • 1/8 inch long
  • light olive brown with darker brown or cream-colored markings
  • reddish appendages
  • body narrows evenly toward the small head
  • strong fliers

cowpea weevil:

  • outer wings tipped with black with two large black dots above¬†

Nesting Habits

  • usually infest legumes in the field
  • indoors: breed continuously in dried legumes stored in warm conditions

Diet

  • legumes in the field
  • dried legumes such as beans, cowpeas, lentils and peas

Significance

  • can damage stored legumes

IPM Recommendations

  • Inspect incoming legumes for beetles and monitor indoor legume storage regularly.
  • Locate and dispose of infested legumes.
  • Store all susceptible food items in pest-proof containers.
  • Clean spilled food products and food storage areas in general.
  • Keep food, especially legumes, in regular rotation.
  • Keep moisture low in food storage areas by improving ventilation.

Additional Resources

IPM for Fabric and Pantry Pests: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)