Rose slug sawfly

The rose slug sawfly (Endelomyia aethiops) is a member of the Tenthredinidae family within the order Hymenoptera. Despite their name, these insects are not slugs, but the larvae of a small black sawfly that can cause extensive aesthetic damage to rose foliage.

The primary hosts for this pest are domestic and wild rose species. The adult females use a saw-like ovipositor to insert eggs into the leaf tissue. Once the eggs hatch, the larvae, which are pale green with orange-brown heads, begin to consume the leaf tissue immediately.

The lifecycle is generally univoltine, meaning one generation per year. The larvae overwinter in cocoons deep within the soil beneath the host plant. They pupate in the early spring, and adults emerge shortly after the first rose leaves have fully expanded to begin the cycle anew.

The damage caused by the larvae is distinctive: they skeletonize the leaves by feeding on the upper surface while leaving the lower epidermis intact. Over time, these areas dry out, turn brown, and give the foliage a scorched, lace-like appearance. Severe infestations can lead to premature leaf drop.

Effective management requires a combination of physical and chemical approaches. Cultural practices, such as tilling the soil around the base of the bushes in late autumn, can destroy overwintering cocoons. During the growing season, applications of appropriate insecticides are effective if applied during the early larval stages.

• Regular inspection of the underside of leaves for early signs of feeding.
• Hand-picking larvae on small rose gardens.
• Application of systemic insecticides or horticultural soaps.
• Soil cultivation around bushes to disrupt the lifecycle.