Blennocampa pusilla

Rose leaf rolling sawfly

Description

Blennocampa pusilla (= Blennocampa phyllocolpa), commonly known as the rose leaf rolling sawfly or small rose sawfly, belongs to the insect order Hymenoptera and the family Tenthredinidae. This insect primarily targets roses (Rosa spp.), especially those in the Rosa rugosa group. The adult sawflies are small, measuring about 4 mm in length. They are predominantly black, wings are slightly darkened, with black veins and a distinct stigma. The larvae - caterpillars, are initially white but later turn a bright green. They exhibit a curved, crescent-like shape, growing up to 7–8 mm in length. Their heads are dark brown. Blennocampa pusilla produces one generation per year. The adult sawflies emerge from mid-May to June. After mating, the females lay eggs, typically placing one or two in a row along the edges of rose leaves. The larvae hatch and begin feeding by rolling the leaf blade parallel to the central vein, creating two tubular structures on either side. By July, the larvae leave the rolled leaves, burrow into the soil, and overwinter before pupating in the spring.