Willow: Poplar and willow borer

Biology

The adult poplar-and-willow borer is a black and white weevil (a flightless beetle) about 3/8″ long. The larvae are white and legless and mine beneath the bark and in trunk and branches. Feeding larvae expel large quantities of frass (sawdust-like excrement) through holes they keep open in the bark. The feeding larvae may girdle branches, resulting in leaf wilt and eventual branch death. When mature, larvae are approximately 1/4″ long. Severe infestations cause swollen, lumpy bark, bark scars with exposed wood, and sometimes considerable production of shoots from old wood. Willows are preferred, but the borer will also attack poplar species.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Remove seriously infested trees.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• None recommended

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