Raspberry beetle (aka Western raspberry fruitworm)

Small yellowish-brown beetles 4-5 mm long feed on black raspberry buds and emerging leaves in late April and May throughout Western Washington, creating characteristic slits between leaf veins. Infested blossoms develop into misshapen or stunted berries. Larvae tunnel into young fruit and feed on the receptacle for 30 days, causing fruits to shrivel, drop prematurely, and become unmarketable.

Adult beetles overwinter in the top 3 inches of soil and emerge as temperatures warm. Inspect buds and new growth for damage; prune off heavily infested shoots. For commercial plantings, insecticide applications at early bloom protects developing fruit. Home gardeners can tolerate cosmetic damage.