Adult: Dark bronze or black beetle, shiny, copper red neck. Slender, about 1/4 inch long. Larva: White, flat head. Slender, up to 3/4 inch long.
Blackberry, dewberry and raspberry.
Adults eat margins of leaves. Larvae tunnel canes, causing spindle shaped swellings on surfaces.
Eastern half of United States.
Adults emerge from canes in late spring. Females lay eggs on bark or inside new growth canes in late spring. Galls form where eggs are inserted or canes may break at these junctions. Larvae hatch from eggs and enter canes through leaf axils, tunnelling through the sapwood to the hardwood, and, finally, the pith where the larvae stays through pupation until spring. Galls may appear in late summer where girdling has occurred.
During winter pruning, if more than 10% of the primocanes are infested then treat.
Cut out and destroy swollen, infested canes.
The rednecked cane borer is parasitized Barichneumon sp. and other species.
Apply a registered insecticide at intervals of 7-12 days from the apperance of the first beetles until early June, usually two sprays are all that are necessary. Spray toward base of canes.
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)