Several species. Adults: Yellow to brown beetles, 1/4 inch long. Larvae: Brown and white, up to 1/8 inch long.
Blackberry, dewberry and raspberry.
Adults make long, narrow slits in blossom buds and newly formed leaves. Larvae feed in berries.
In Northern United States.
Adult raspberry fruitworm beetles overwinter in soil around host plants, emerging in spring. The beetles begin feeding on tender new leaves and, later, on flower buds. Females deposit eggs on or inside flower buds or young fruit. Larvae bore into fruit and fall to the soil where they pupate when fruit ripens.
Remove damaged and rotting berries as soon as possible.
Botanical insecticide dust or spray applied 3 times at 10 day intervals (starting 7 days after the first blossoms appear) should help reduce raspberry fruitworm populations.
Treat with a registered insecticide, starting when flower buds appear and make the second application just before blooming.
Notice: Because pesticide labels can change rapidly, you should read the label directions carefully before buying and using any pesticides. Regardless of the information provided here, you should always follow the latest product label when using any pesticide. If you have any doubt, please contact your local Extension agent or pesticide dealer for the latest information on pesticide label changes.
Disclaimer: Commercial products named on this site are for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products which also may be suitable.
Prepared by Alexandra Spring and Eric Day (Modified from a publication by the USDA)