Sooty Hairstreaks vs. Boisduval's Blues

Sooty Hairstreaks (Satyrium fuliginosa & semiluna) and Boisduval’s Blues (Icaricia icarioides) share some of the same larval host plants and are easy to confuse with each other without a closer look. Female Boisduval’s Blues often have a light dusting of blue scales on the dorsal surface (1), and may have a dark gray bar in the DFW cell (2). Sooty Hairstreaks never have these two features and their ventral spots are almost always smaller and fuzzier than Boisduval’s Blues, especially between their VFWs (3). Marginal VHW spots are slightly chevron-shaped on Boisduval’s and round on Sooty (4), or may be missing on both species (5).