Ancyloxypha numitor, the Least Skipper, can be found in numerous US states in all regions of the country.
Favorite nectar plants: Asclepias, Bidens, Cirsium, Erigeron, Liatris, Pelargonium, and Vernonia.
USDA Growing Zones for these plants include: 3,4,5,6,7,8,9,10,11

Host plants:
Mimosa
Phaseolus
Pithecellobium
Senna spectabilis

PD image
Zoological Illustrations Volume II Series 2

CC0 image courtesy of
Alan Schmierer

CC 3.0 image courtesy of
Thomas Bresson