Pear Sawfly

    Pearslug/Pear Sawfly

    Caliroa cerasi

    pear sawfly

    Adult pear sawfly (Cheryl Moorehead, Bugwood.org)

    pear sawfly larvae

    Pear sawfly larvae (Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org)

    pear sawfly damage

    Pear sawfly damage (Lesley Ingram, Bugwood.org)

    Pest Description

    • adults: 1/5 inch; shiny black wasps; fly-like
    • larvae: up to 1/2 inch long; covered in olive green to black slime; sluglike
    • mature larvae: orangish yellow without the slimy coating

    Host Plants, Diet & Damage

    • primarily pear and cherry; cotoneaster, hawthorn, mountain ash, plum
    • feed on plant tissue
    • skeletonize the upper surface of leaves
    • severe damage can cause brown leaves and leaf drop
    • 2nd generation typically causes most of the damage

    Biology, Life Cycle & Damaging Life Stage

    • overwinter as pupae in the soil
    • pupate in spring; adults emerge in late spring and mate
    • females lay eggs into upper surfaces of leaves
    • 1st generation eggs hatch in early summer; larvae develop through late July
    • mature larvae drop from plants and pupate in the soil
    • 2nd generation larvae are present in late-August and September
    • mature larvae drop from the tree and overwinter as pupae in the soil
    • two generations per year
    • larvae are the damaging stage

    IPM Recommendations

    • Manage trees to improve or maintain health.
    • Monitor in July, late-August and September for larvae.
    • Damage from low-level populations can be tolerated.
    • Wash larvae off with a strong spray of water.
    • Apply an insecticide (carbamate; insecticidal soap; pyrethroid; spinosyn) to foliage when larvae are present.

    For more information, see our Pear Sawfly fact sheet.