Newly hatched larvae bore into the leaves and feed for the rest of the season. The larvae mine from the tips of branchlets toward the bases and allow the frass to collect in the tunnels until winter. When mining is resumed the following spring, the frass is expelled from the mine. Larvae will sometimes leave old mines and begin new ones. May. The pupal stadium is 3 to 5 weeks.
Pupae face the exit hole.
Some control may be obtained by pruning out infested tips in the fall. Hymenopterous parasites also help control the population.