Northern Prairie Wildlife Research Center
Red, brown, or black, patterning variable. Hairy caterpillar distinctively beset with black (sometimes white) lashes on first 2 thoracic, as well as first and eighth abdominal segments. Longer setae in lashes broadening to tips. Other setae in white, rusty, or black tufts borne on low warts. Whitish abdominal spiracles often in charcoal patches bordered below by broad, oblique creamy spots that may form wavy subspiracular band. Black zigzag (P. acronyctoides) with more white, lacking long pencils on thorax, and without apically broadened setae; firs, hemlocks, and other conifers. Food: pines, larches, and spruces. Caterpillar: May to October; 2 generations in North.