RECOGNITION Black body mottled with yellow, especially laterally. Long, black, shiny spines arise from irregular blackened patches. On midabdominal segments each seta arises from its own blackened plate, except above spiracle, where two setae share single plate. Larva to 3.5cm. Painted Lichen Moth (Hypoprepia fucosa) smaller, marked with less yellow; middorsal stripe less differentiated (inset).
OCCURRENCE Woodlands and forests from southern Canada to Florida and Texas. One generation with mature caterpillars from May to July northward; two or three generations in Missouri with mature caterpillars nearly year-round.
COMMON FOODPLANTS Lichens and blue-green algae (cyanobacteria) growing
on tree trunks, fallen logs, and rocks.
REMARKS Adults of eastern Hypoprepia vary considerably in different parts of the Southeast, so much so that some lepidopterists feel additional species will eventually be recognized. Hypoprepia and other lithosiine arctiids have anal combs that allow them to eject their fecal pellets distances of 30 or more body lengths.
The comb, which protrudes from the underside of the anal plate, is hooked under a torus of rectal tissue. Hemolymph (blood) is then forced to the last body segment, where pressure becomes so great that the comb slips and the fecal pellet is ejected with great velocity. “Fecal flicking” foils parasitic and predatory wasps that would use volatiles from the excreta to locate their intended victims. Hypoprepia caterpillars are cannibalistic on smaller larvae and pupae. The caterpillar overwinters.
