SOUTHERN and sweetflag SPREADWINGS
I feel safe calling this one a male Southern Spreadwing because of the early date. Southern Spreadwings start flying earlier in the year than Sweetflags. This male Southern Spreadwing was photographed on April 17, 2019, at Grant Park in Centerville. Sweetflags don't start flying until later in May. Both species can fly until late in the year. (My personal late sighting is October 22nd.)
This is a male Southern Spreadwing. Males of this species are very similar to male Sweetflag Spreadwings. You need to find a female to identify them. Fortunately, females are easy to distinguish (see below). (Note that Northern Spreadwings also look extremely similar to both species, but Northern Spreadwings are not known to occur in our part of Ohio.)
This is a female Sweetflag Spreadwing, photographed at Cox Arboretum. We can tell she is a Sweetflag by looking at the abdomen tip. This female has a large ovipositor that extends beyond the tip of her abdomen.
This is a close-up view of a female Sweetflag Spreadwing's large ovipositor.
This is a female Southern Spreadwing, photographed at Oakes Quarry. Her abdomen tip is not as large as a female Sweetflag's.
Mated pair of Sweetflag Spreadwings at Cox Arboretum. I have also found Sweetflags at Caesar Creek and Beavercreek Wildlife Area.
For comparison, here is a female Southern Spreadwing's ovipositor. Much smaller!
Lateral view of another female Sweetflag Spreadwing.
Another female Southern Spreadwing. This individual is older than the one above. Note the difference in eye color and the pruinosity here.