The pearl crescent is a common small butterfly in the brush-foot family. They produce several broods each year; the adults can be seen flying in Maryland from early May to November. They range from the Rocky Mountains east in the US, southern Canada, and northern Mexico.
Caterpillar host plants include a large number of aster (Symphyotrichum) species. Adults feed on plants in the dogbane, aster, and mustard families (Apocynaceae, Asteraceae, and Brassicaceae).
Like many butterflies, especially brush-foots, they’re often found near puddles. The one pictured here was one of about a dozen flitting about the mud on the banks of the Potomac River one morning in mid-October. The deep depressions to the left and bottom of the picture are dogs’ pawprints.