A northerly distributed Catocala whose larva can be found on Populus and Salix. In the species group comprised also of amatrix, cara and carissima. The beige-colored cranial protrusions characteristic of cara and carissima are less pronounced in concumbens and its head capsule has darker markings, the body ground color is darker and more brown, the A5 hump less bulbous, and the venter with usually faint red/pink tinge and black spots throughout (spots limited to A3-A5 in cara and carissima, and typically just A1-A5 in amatrix). Wild larval foodplant records in southern Connecticut Populus deltoides to date.