The raspberry cane borer damages raspberry plants from early June to late August. Females puncture two rows of holes in raspberry stem tips and lay their eggs between them. The punctures restrict sap flow resulting in wilting, blackening and finally death of the tip.
Adults are slender, one-half inch long beetles with a bright orange body and two to three black spots. The larvae are white legless grubs found in the interior of the cane. They move down the cane as they feed.
Remove and destroy infested stems several inches below the wilted tip as soon as the damage is found.
For more information, see the following Colorado State University Extension fact sheet(s).
For more information, see the following Planttalk Colorado™ script(s).