Public-Health Pesticide Applicator Training Manual (original) (raw)

The immature stages of several species of moths in states east of the Rocky Mountains are venomous to humans because of their external poisonous spines and hairs. Some species are infrequently encountered, but three species are more nationally common.

The Io moth caterpillar, Automeris io, when fully grown is about 2 to 3 inches long with a row of tubercles armed with green and black spines, many of which are connected to poison glands. This insect undergoes one or two generations per year and overwinters in the pupal stage. The caterpillars are encountered as they feed on favored vegetation.

The white to dark gray puss caterpillar, Megalopyge opercularis, is about 1 inch long when fully grown and completely covered with venomous hairs that resemble tufts of cotton. The moth undergoes two generations a year in the Southeast, during which the caterpillars feed on shrubs and bushes where they pose a threat to humans.

The saddleback caterpillar, Sibine stimulea, feeds on shrubs, bushes, trees and other plants. Easily recognizable by the brown or purplish saddlelike coloration on its back, it has multiple stout, venomous spines along the sides of the body and the four tubercles.