Weakened, diseased, insect-damaged or shaded trees, particularly those already struggling with poor soil or moisture conditions, are especially vulnerable. Severely defoliated evergreens are less likely to survive than other trees. Gypsy moth infestations are heaviest in central and southern Maine. In addition to defoliating trees, they are also nuisance pests because of wandering caterpillars, droppings, pupal cases and egg masses on homes and the spinning down of young caterpillars. Tiny hairs from the caterpillars can irritate the skin of some people.
Reactions usually subside in five to seven hours.
If consulted, a doctor should be informed of the possibility of contact with gypsy moth caterpillar hair. It takes up to a month for all the eggs to hatch. For this reason, it is common to find caterpillars of various sizes at the same time. The larvae soon crawl into treetops, where they spin down on lines of silk to be blown to other places. Feeding by the young caterpillars on underside of leaves usually goes unnoticed.