Pest description and damage The rose midge is a tiny (about 0.05 inch in length) yellow-brown or reddish fly that lays its eggs in newly developing bud and shoot tips. The hatching maggots feed on the growing tips or new rose canes. The mature maggots are about 0.0625 inch long and white to reddish in color. New buds and shoots are deformed and killed, and the dead tissues turn brown or black. Abnormal flowers develop from damaged buds.
Biology and life history The insect overwinters as a pupa in the soil under plants. Adults emerge in spring, and females lay eggs under the sepals of flower buds or on expanding leaf buds or shoots. The larvae emerge, and their feeding causes damaged tissue to turn brown, then black. The larva then drops to the soil to pupate. There are several generations per year.
Cut out and destroy infested tips.
See Table 3 in: