Northern Prairie Wildlife Research Center
Small dark brown caterpillar with arched eighth abdominal segment. Anterior abdominal segments with oblique pale stripes that pass through spiracles onto subdorsal areas of adjacent segment; stripe on seventh segment pronounced. Faint-spotted palthis (P. asopialis) with denser, whiter, and more toothlike projections over body surface. Food: forbs, including crops, as well as forest hardwoods and softwoods. Caterpillar: June to November; 2 or more generations in South, 1 in North.