Io moth

Automeris io moth

Common Name: Io moth

Scientific Name: Automeris io

Season: Usually two generations in the Northeast.

Food: Feeds on many different trees, shrubs, legumes, and grasses (this one was feeding on black locust).

Ecology: Adults emerge during late morning or early afternoon, and mating takes place in the late evening. Females lay clumps of eggs on leaves or stems of the host plants. Young caterpillars feed together as a group and move in long “trains” while older caterpillars feed alone. Papery cocoons are spun in litter under the host plant or in crevices.

Adam Mitchell Photos


Caterpillars of the io moth are dangerous to touch, even young caterpillars such as these (mature caterpillars become green). The large spines that protrude from their backs can cause a stinging sensation to the fingers, similar to stinging nettle. The adults, however, are harmless.