PEST PROFILES: WASPS
Click on image to view larger. Sawflies and rose slugs
These primitive wasps called sawflies because females of most species have a saw-like structure on the abdomen tip used to insert eggs into plant tissue. Larval stages are caterpillar-like, with a well-developed head capsule and 3 pairs of true legs behind the head; hairless body. Some sawfly larvae are slug-like, appearing slimy, unsegmented and translucent, greenish to black, while others appear wax-covered in some of their developmental stages. Adults vary from 3/4 to 2 inches long.
Adults are rarely seen and do not sting. Most sawflies are somewhat host-specific. Larvae of some species are leaf rollers, web formers, leaf skeletonizers, leafminers, shoot borers, or cause plant galls. Adults can be found on flowers.
Life cycles vary by species, but generally they overwinter as a pre-pupa in a cocoon in the ground or other protected place, pupating in the spring. In early summer, adults oviposit eggs in or on plant tissue. Larvae develop through several stages (up to 6 instars) before pupating, producing 1 generation per year. Some species have several generations annually.