A large and frequently encountered Populus-feeding Catocala larva especially in temperate parts of North America. Prominent A5 protuberance, long lateral filaments; head capsule with less pronounced cranial projections as in cara and carissima, and with a thicker and more prominent lateral band than those species. Ground color typically warm gray to brown, often with darker dorsal and lateral stippling/striping. Venter with orangish hue throughout, black ventral spots extending above A3 to head (these not present in cara and carissima) but either lacking or reduced beyond A5 (concumbens with shorter lateral filaments, more extensive reddish venter hue, and dark spots extending from A5 to rear). Typical wild foodplants of amatrix in eastern North America include Populus deltoides and Populus nigra, but also occasionally other Populus and less commonly Salix.