Leafcutter Bees

    Leafcutter Bees

    Megachilidae spp. 

    leafcutter bee

    Leafcutter bee (Johnny N. Dell, Bugwood.org)

    leafcutter bee damage

    Leafcutter bee damage (Whitney Cranshaw, Colorado State University, Bugwood.org)

    leafcutter bee nest

    Leafcutter bee nest in wood made from leaves (Rodtuk, Flickr.com)

    Pest Description

    • adults: 1/5 inch – 1 inch; mostly small bees
    • some resemble small honey bees (black and yellow)
    • carry pollen on the underside of their abdomen
    • important native pollinators

    Host Plants, Diet & Damage

    • rose; lilac; Virginia creeper; ash; any broadleaf, deciduous plants
    • nectar and pollen
    • cut and remove 1/4 inch – 1/2 inch ovoid chunks of leaf tissue from leaf margin
    • may sting, but sting is mild; non-aggressive
    • damage is aesthetic, not a threat to plant health

    Biology, Life Cycle & Damaging Life Stage

    • overwinter as larvae within cells created by the parent bee
    • active in late-June and July
    • one generation per year
    • solitary; they do not make large nests like honey bees
    • nests typically consist of less than 12 cells
    • nest in the soil, in wood or in hollow plant stems
    • leaf pieces are used to construct cells within the nest
    • queen provisions larvae with pollen-nectar balls within individual cells
    • adult bees are the damaging stage

    IPM Recommendations

    • Damage is aesthetic; tolerate leafcutting bees.
    • Leafcutter bees are important native pollinators and should be preserved, if possible.
    • Reduce/eliminate nesting habitat by sealing holes in wood.
    • Use cheesecloth to exclude bees from individual plants.