 nigrescens" from the northeastern United States may be a melanistic morph of the nominate subspecies rather than a valid taxon in its own right.In Illinois, adults have been recorded as feeding on nectar from "Rhus copallina", "Cicuta maculata", "Eryngium yuccifolium", "Oxypolis rigidior", "Pastinaca sativa", "Asclepias incarnata", "Erechtites hieracifolia", and "Pycnanthemum tenuifolium".In California, the adults of both sexes have been collected while feeding on aphid honeydew and at flowers of "Hazardia squarrosa", while females alone have been taken at flowers of "Celosia floribunda" and males at "Eriogonum fasciculatum", "Koeberlinia spinosa", and
"Melilotus albus".