This is a Lancet Clubtail. My personal nickname for the Lancet Clubtail is "Lilliputian Clubtail" because they are so small compared to most of the other clubtails I see. Lancet Clubtails get their name from a downward-projecting blade on the cerci, which distinguishes this species from the Ashy Clubtail in close-up photos. 

Ashy Clubtail, photographed at Germantown MetroPark. This species has a lot of variation, depending on geographic region. In other parts of North America, Ashy Clubtails have much duller colors and little or no yellow on the top of the club (Segment 9). However, most of the Ashy Clubtails in our area are fairly brightly-colored. 

Ashy Clubtails have an early flight period. I have found them from mid-May through mid-June. They are fairly widespread. There is a good population at Germantown MetroPark. I have also seen Ashy Clubtails at a few of the Beaver Creek Wetlands parks (including Siebenthaler Fen), Spring Lakes Park in Bellbrook, Clifton Reserve, and Pointe North in Urbana. 

I have found Lancet Clubtails at Pointe North in Urbana, Germantown MetroPark, Clifton Gorge, and the Beavercreek Wildlife Area. They typically fly in late May and early June, although I have one late sighting on July 11th. 

Ashy Clubtail cerci

Lancet Clubtail cerci

Teneral Lancet Clubtail 

This is another Ashy Clubtail. Ashies can be difficult to distinguish from the similar Lancet Clubtails. In the field, Lancets are noticeably smaller. Ashies are longer and thinner; Lancets are short and chunky. The club is very narrow on an male Ashy Clubtail; it is a bit wider in a Lancet. Lancets often have a long yellow streak on the top of Segment 8, while Ashies usually have a shorter streak or yellow triangle. Also, adult Ashy Clubtails often have violet-gray eyes rather than the blue-green eyes of a Lancet Clubtail. (But some mature Ashies do have blue-green eyes, so don't rely on this feature alone.) The best way to distinguish these two species is with a close-up photo of the cerci.