United States and Canada
This is the most widesprea d tropical dasher in North America. Its face is pale yellow. The top of the frons is brown in females and young males, but becomes metallic blue in mature males. The front of the thorax is brown, with two pale green stripes, that don't reach the alar carina. The sides are green with three brown oblique stripes. The middle one is usually forked at its upper end, often joining with the stripes on either side, forming a IYI pattern. The underside of the front femur is green in females and young males with the rest of the leg black. The wings are clear, with only a flavescent tinge basally and a small brown basal spot in the hindwing. The black abdomen is slender but widens slightly at segments 7-9. There are a row of greenish spots dorsolaterally on segments 1-7, with those on segment 7 most pronounced. The remaining abdominal segments and caudal appendages are black. Mature males develop a pruinose grayish color on the thorax and abdomen. Females are similar to males but lack the pruino sity and their abdominal spots are larger throughout.
Size: Total length: 30-36 mm; abdomen: 18-25 mm; hindwing: 24-30 mm.
Similar Species (south-central US): Three-striped Dasher (M. didyma) and Blue Dasher (Pachydiplax longipennis) are generally smaller and have three distinct lateral thoracic stripes forming a III pattern. The smaller female Spot-tailed Dashers (M. aequalis) has a WII lateral thoracic pattern and prominent triangular spots dorsally on abdominal segment 7. Swift (Dythemis velox) and Black (D. nigrescens) Setwings are larger, have dark wingtips and have a different lateral thoracic pattern. Pale-faced Clubskimmer (Brechmorhoga mendax) is much larger. Female Seaside Dragonlets (Erythrodiplax berenice) have a prominent ventrally projecting ovipositor.
Habitat: Heavily vegetated ponds and lakes.
Natural History: This species has been reported as far north as Franklin County, Arkansas. Although it is widely distributed it only becomes locally common from Central Texas southward where it breeds. One study documented females ovipositing as they hover low over the water, 0.25 m, extrude egg masses approximately 2 mm in diameter and flick their abdomen upwards to release them. They will also extrude eggs on floating vegetation. This species is often found perched on thick vegetation surrounding the ponds it haunts. It is often recognizable because of its common habit of raising its abdomen, with pale white spots, nearly vertically over its brilliant iridescent green eyes. This species is found year round throughout much of its range, and the limited flight season stated above may not be completely representative.
Distribution: Arkansas, Texas south through Mexico and West Indies to Panama.
Source: Abbott, J.C. 2006-2010. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at OdonataCentral.
Edited by Drew Weber (9/24/2015).
