Granary Weevil - School IPM - USU Extension

    Granary Weevil

    Sitophilus granarius

    Granary weevil

    Granary weevil (Pest and Diseases Image Library, Bugwood.org)

    Granary weevil

    Granary weevil (Pest and Diseases Image Library, Bugwood.org)

    Granary Weevil

    Granary weevil in wheat (Clemson University, Bugwood.org)

    Identification

    • 1/8 - 3/16 inch long
    • reddish brown
    • elongated oval pits on the thorax
    • tuck in legs and remain motionless when disturbed; cannot fly
    • larvae: small, white legless grubs with brown head capsules

    Nesting Habits

    • lay eggs in small holes chewed by females
    • larvae develop inside kernels of grain

    Diet

    • feed on whole corn, wheat, barley, rice, pet food, bird seed, sunflower seeds and occasionally old pasta, chestnuts and acorns

    Significance

    • attack a wide variety of grains
    • primarily distributed by people via infested food

    IPM Recommendations

    • Use traps to monitor activity in structures, pantries and bulk grain storage.
    • Improve sanitation procedures in affected areas.
    • Inspect all incoming food items for pests.
    • Store all susceptible food items in pest-proof containers.
    • Dispose of infested food items.
    • Keep moisture low in food storage areas by improving ventilation.
    • Keep food in regular rotation.

    Additional Resources

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