Boysenberry: Raspberry crown borer

Biology

The adult raspberry crown borer is a clearwing moth with a wingspan of 1″ to 1 1⁄2″. The moth closely resembles a yellowjacket. Females lay eggs on the canes or leaf margins. The caterpillars hatch by fall (around October) and overwinter in small cells near the base of the canes. In the spring, the larvae tunnel deeper into the canes and feed inside the canes. The canes may appear swollen or galled as a result. The caterpillars spend a second winter in the canes before emerging as adults the following summer. The larvae are white with brown heads. During the second winter they are typically 1⁄4″ long. They reach their full size of 1″ to 1 1⁄2″ long by the following summer. The borers can cause extensive damage to the canes, roots, and crown, weakening blackberries and related varieties including ‘Logan’ and ‘Boysen’ berries. They may cause death of raspberries.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

• Cut or dig out and destroy galled canes and infested crowns in late fall or early spring.
• Remove other hosts in the area, including wild blackberries.

Chemical Management

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

• No products are registered for home use for this pest.