Picture of Sawfly larva

Picture of Adult Sawfly

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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 cycle:
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.