Rose slugs are the larvae of sawflies, non-stinging wasps. At least three different types of rose slugs cause damage to roses: the European Rose Slug, the Bristly Rose Slug and the Curled/Curly Rose Sawfly. Rose slugs feed on the upper or lower surface of leaves between veins, leaving behind translucent membrane. Larger species can chew larger holes, causing leaf skeletonization. Most university Integrated Pest Management sites recommend hand picking the larvae. Insecticidal soap and horticultural soil are also efffective. Bacillus thuringiensis is ineffective because rose slugs are not true caterpillars.