Fissicrambus mutabilis

On Block Island, this species is highly variable, with many individuals having prominently streaked forewings. Based on online images and the specimens at the CUIC, most populations of this species do not include the streaked color morph. DNA barcoding results indicate the existence of at least one undescribed species near mutabilis.

Bivoltine locally with a gap between generations in mid- to late July. The second generation is evidently larger and with a tighter flight window. iNaturalist records indicate that the species is bivoltine from the north end of its range in southern Ontario and Atlantic Canada, where it flies mainly in early July and late July, south at least to Maryland; on wing April to September with July-August peak in Southeast US, indicating three or more generations. This is by far the most abundant moth species by count at AH but is uncommon away from frequently mowed lawns and meadows.