Northern Prairie Wildlife Research Center
White dorsal patches bordered in black surrounded by orange; an off-white spiracular line with two blue patches per segment above it; dense white hairs laterally. This species is common on many broadleaf trees, in particular bitterbrush, red alder, and snowbrush, during May and June. The extensive blue coloring is unusual in caterpillars and typical of the genus Malacosoma. This caterpillar is similar in appearance to Malacosoma disstria but differs in the pattern of the white dorsal markings.