Canes infested by raspberry cane borer show tip dieback. Wilted tips are usually observed in June. Cane tips wilt, blacken, and may fall off after they are girdled by the female beetles. This beetle's black antennae are nearly as long as its body. Adult beetles feed on the epidermis of cane tips from June through August.
Females use their mouthparts to chew two rings of punctures around canes.
They then deposit an egg between the rings of punctures. Eggs hatch into larvae, or grubs, that feed inside the cane. Larvae bore down to the base of the cane by fall, and into the crown by the next summer. As soon as the wilted tips are noticed, they should be cut off, several inches below the lowest girdle mark. Remove the infested tips from the field and destroy them.