Crops Affected: All cane berries in the genus Rubus, including raspberries and blackberries

States Affected: All states

Life Cycle: The crown borer follows a 2-year life cycle, primarily as a larva tunneling in lower cane, crown, and roots of cane berries. Adult moths emerge from pupae in late summer and fall, with pupal skins clinging to raspberry cane bases. These day-flying moths mimic stinging wasps for protection. Eggs are singly laid on bramble leaves. Larvae crawl down canes to form a hibernaculum near the soil. In spring, they chew into the cambium layer, tunneling into the crown and upper roots. After a second winter, larvae bore upward in the cane pith, completing growth in the second summer, followed by pupation.

Damage: Larvae tunneling in crowns and upper roots reduce plant growth and vigor and reduce yield. Early signs of infestation are the wilting and dying of foliage on canes in late spring and early summer. Canes with significant damage may become spindly and break off at the crown. Canes which are not killed directly may not survive the winter frosts. Look for holes filled with sawdust-like frass produced by the larva in the crown and upper roots. Damage from larvae may lead to secondary infections by pathogens.

Season to Trap: July to September

How To Use: Hang trap with lure inside at shoulder height near at risk or affected crops. Replace lures every 30 days through the season, and replace traps when 70% saturated. Adult males are attracted to the pheromones in the lure and the color of the traps in this kit. Once they land on the sticky trap, they become ensnared, never to mate or lay eggs again.

Additional IPM Solutions: Avoid practices that destroy or disrupt native beneficial insects. Remove unwanted wild bramble species to prevent alternate host sites. Remove infested canes. Insecticides when adults are active, to target young larvae before they enter the canes, may have some effect.