Northern Prairie Wildlife Research Center
Slender brown twig mimic checkered with white, gray, and black, much like bark of its hosts. Head somewhat dorsoventrally flattened, held forward, triangle darkened, antennae whitish. No prominent warts, although posterior half of first 6 abdominal segments somewhat thickened laterally and ventrally, with transverse furrowing. Each of these same segments bears broad pale patch in front of spiracle. Anterior face of prolegs lightened. Food: junipers and cedars. Caterpillar: May to October; 2 generations in North.