Large rose sawfly

Adults have a bright yellow abdomen contrasting with black legs, thorax, and head, and the antennae look like a single long fused segment rather than the branched or feathered antennae of many other sawflies. The wings often show a faint blue metallic sheen.

Females cut a row of slits into rose stems to lay their eggs, and the pale green larvae with black spots that hatch from them feed together in groups on the leaves. Two or sometimes three generations can occur between spring and autumn.