Pest description and damage The adult insect is a golden yellow moth about 0.5 inch long. The larvae are small, pale yellow to green caterpillars, 0.125 to 0.25 inch long. The larvae mine leaves during the early part of their development. During later stages of their development, they also roll the leaves and skeletonize them.
Biology and life history The insect overwinters as a pupa in rolled leaves, or possibly as a larva in a mined leaf. After the adult moth emerges, eggs are laid singly on the underside of leaves. The larvae emerge and mine into the leaf, causing the mined tissue to turn brown. They then emerge from the leaf and roll it over their bodies with silk for protection as they feed. Later, they select an undamaged leaf, roll it up, and pupate in it. The adult moth emerges about a week later. There may be two to three generations per year.
Pest monitoring Observe early spring growth for rolled leaves and feeding damage.
Very low temperatures in winter significantly reduce overwintering populations. Spiders and parasitic/predatory insects greatly reduce populations throughout the year.
Hand-pick larvae if found. Removing rolled leaves in winter can reduce next year's population.
See "Leafminer" in:
For more information
Baker, J.R. Azalea leafminer (http://ipm.ncsu.edu/AG189/html/azalea_leafminer.HTML)