Dogwood Sawfly Larvae - Macremphytus testaceus

Sawfly larvae may look like caterpillars, but they are actually wasps. Macremphytus species, in particular, are an interesting genus of sawfly because the second larval instar is covered in a white waxy covering, while the last larval instar is yellow and black. The caterpillar-like larvae feed on the leaves of dogwood trees and shrubs (Cornus sp.). The larvae can cause considerable defoliation since often they feed in groups, but they don't usually kill the plants.

I find masses of these larva on the same few trees each year. They completely defoliate it, and I have no idea how it survives from year to year!