The preferred host of this species is a red maple, yet it frequently defoliates sugar maple as well. Infestations usually encompass fewer than 50 acres (20ha), and last for 2 to 3 years. However, there have been exceptions: an Ontario outbreak in the 1940s lasted for 10 years, and during the early 1970s, defoliation in Pennsylvania affected more than 27,000 acres (11,000 ha). Heavy defoliation can significantly reduce sap quality.

The brightly colored moths of this species have a wingspan of 1.5 to 2.0 inches (37 to 50mm). The woolly body is creamy yellow on top and rose to pink underneath. Forewings are rose-pink at the base and tip, wit ha center band of yellow. Hindwings usually are pure yellow but may be faintly streaked with rose-pink. Adults, sometimes called rosy maple moths, frequently congregate around lights at night. The color of mature caterpillars varies, but each usually has a series of longitudinal light to dark green stripes along the back and sides (Fig. 34). The most distinctive feature is a pair of black “horns” on the back of the second body segment, immediately behind the cherry-red head.

The caterpillars initially group and feed together; these young larvae have shiny black, not red, heads. As they mature, the insects disperse from their group and become solitary feeders.