Species velox Hagen, 1861 [Dythemis]
This is a clear-winged species similar to Black Setwing (D. nigrescens), but the top of the frons is dull and never metallic. Its face is olivaceous in tenerals and females and dark brown in older males. The lateral thoracic pattern of dark stripes is YIY. This pattern is nearly always visible as older males generally lack heavy pruinescence. The wingtips are dark and usually have 3 rows of cells between vein A2 and the hindwing margin. The wings become amber in older individuals and have a spot of brown at the extreme base in both wings. The legs are black. The abdomen has pale yellow-greenish dorsolateral spots on segments 3-7 that become most conspicuous on segment 7 and sometimes are lacking on 5-6.
Total length: 42-50 mm; abdomen: 25-32 mm; hindwing: 30-36 mm.
This species is closest to Black Setwing, but Swift Setwing has a YIY lateral thoracic pattern, not HII or HIY. It also has darker wingtips and lacks a metallic vertex. See similar species listed under Black Setwing for details on separating this species from others.
Lakes, ponds and borrow pits as well as creeks, streams and rivers with moderate current.
This is the most widespread of the North American setwings and it is apparently continuing to expand its range. Bick (1957 ) didn't find it in Louisiana, but Mauffray (1997), 40 years later, reported that it was common in the northern part of the state, west of Baton Rouge. It is often found along ponds, borrow pits, streams, creeks and rivers where it perches high on tall grasses and weeds with the wings depressed downward and the abdomen held above the rest of the body, sometimes considerably so. Males patrol small areas along the stream and creek edges where they may be flighty.
Southern U.S. from Florida to Arizona, Mexico and Cuba.