She said this species is fairly easy to tell apart from the other small black butterflies by the wavy, or scalloped wings. These butterflies belong in the family hesperiidae with the skippers . Most skippers are tiny butterflies with upfolded wings when in the resting position. This species is a spread-wing skipper measuring up to 1 1/4 inches and rests like other butterflies with its wings open. They are dark with checkered fringe and tiny transparent spots on their wings. Those spots are visible in this picture as two tiny dots near the corner of the forewing.
Hayhurst scallopwings can be found throughout the eastern portion of the United States as well as in Texas. They occur in a wide variety of habitats including open woodlands, backyards, roadsides, and weedy lots. The adults nectar at most any flower but seem fond of peppermint,marigolds, clover, cucumber and dogbane.
Males will perch low in vegetation to attract passing females and will mate with receptive females. Eggs will be laid one at a time on the leaves of host plants such as Lambsquarters, in the goosefoot family, and occasionally chaff flower (Alternanthera) in the pigweed family. In Missouri there will be two broods, one in the spring and one in the late summer.
Thanks Betsy for the ID on this subtly beautiful butterfly.