Bean and Cowpea Weevils - School IPM - USU Extension

    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)