This is a Horace's Duskywing on echinacea. This species flies from April through September. In the summer months, their closest look-alike is the Wild Indigo Duskywing. The main difference between the two is that a Horace's Duskywing has a single white dot (glassy cell) near the center of each forewing, while Wild Indigo Duskywings typically lack this dot.

This is a Horace's Duskywing on a faded coneflower. Some Horace's Duskywings have a heavily mottled wing pattern, particularly the females.

Juvenal's Duskywing, photographed April 19, 2016. This is a spring-flying species that flies near wooded areas in April and May. Juvenal's Duskywings closely resemble Horace's Duskywings. The two species can be confusing to separate in the spring months; however, if you see one in June or later, it's probably a Horace's Duskywing because Juvenal's Duskywings only fly in the spring. 

This is a Wild Indigo Duskywing on echinacea. This species flies from May through October and is probably the most common duskywing in our area. Notice that it lacks the single white dot near the center of the forewing.

This is a Funereal Duskywing, a rare stray to Ohio. Funereal Duskywings typically live in the southwestern U.S., but there have been a handful of reported sightings in northeastern states in recent years. Some researchers think that this species might be expanding its range. The gleaming white border on the hindwings is its distinctive feature. 

I have found three Funereal Duskywings, all at Cox Arboretum and all in the month of September: September 11, 2015, September 8, 2017, and September 1, 2018.