Adults of this Cecidomyiid fly are only 3 mm long and difficult to see. This pest is also called cranberry tipworm. Females can lay up to 20 eggs in swelling buds, and white larvae develop inside, damaging young flower and leaf buds. Larvae are yellow-orange and reach only 1 mm when mature. Multiple generations occur each year. Infected buds dry up and disintegrate. Later egg laying occurs on vegetative shoot tips.

Monitor by collecting buds and holding them at room temperature in plastic bags until larvae emerge.