Pest description and damage Adults of this insect are tiny moths. Early instar larvae are flat. The larvae produce blotched mines, which may be more visible on one side of the leaf. Miners spin silk across the leaf surface, which dries and shrinks to create a ridge over the mine. The larvae feed initially on sap, and then feed on tissue inside the leaves during summer. There may be more than one generation per year.
Pick off infested leaves when practical on smaller plants. Aspen and cottonwood trees are very susceptible. Plant resistant tree varieties in areas where serious blotchminer infestations exist.
See "Leafminer" in: