Poplar Borer

    Poplar Borer

    Saperda calcarata

    poplar borer

    Poplar borer (Whitney Cranshaw, Colorado State University, Bugwood.org)

    poplar borers

    Poplar borer adult and larvae (James Solomon, USDA Forest Service, Bugwood.org)

    poplar borer damage

    Poplar borer damage (Minnesota Department of Natural Resources, Bugwood.org)

    Pest Description

    • adults: ~ 1 inch; gray with black speckles and brown markings
    • larvae: up to 1 1/4 inches long; white grubs without legs

    Host Plants, Diet & Damage

    • aspen, cottonwood, poplar and willow
    • larvae feed on sapwood and heartwood
    • cause structural weakness of branches and stems
    • wounds allow secondary pathogens to invade
    • boring holes ooze rust-colored sap and frass
    • major pest of aspen trees in landscape and forest settings
    • smaller diameter trees can be killed

    Biology, Life Cycle & Damaging Life Stage

    • overwinter as larvae in the wood
    • adults fly from mid-June through August
    • one generation is completed in about 3 years
    • larvae are the primary damaging stage

    IPM Recommendations

    • Avoid planting aspen at low elevation valley sites.
    • Manage trees to improve or maintain overall health.
    • Remove and chip/burn heavily infested trees.
    • Spray Steinernema nematodes into active larval galleries.
    • Apply a pyrethroid insecticide to the bark in early June.

    For more information, see our Poplar Borer fact sheet.