United States and Canada
The male has a blue face with a black head dorsally. The mesepisternum is black medially, pale blue or yellow laterally and confluent with the dorsal half of the mesepimeron. The remaining ventral half of the mesepimeron is dark and the remaining pterothorax is pale with a dark stripe of variable width running along the metapleural suture. There are a pair of dark marks ventrally on the thorax, posterior to the legs. The abdomen is slender, especially towards its middle. A ventrolateral spot is present on segments 3-5. Segments 6-7 are dark ventrolaterally. These areas along with segments 1-2 and 8-10 become heavily pruinose with age. Females are sim ilarly colored to males. The markings above the mesopleural suture are similar to the male, but the pterothorax is pale ventrally except for a dark spot just above the anterior end of the metapleural carina and a posteromedial spot on the sternum. The coloration of abdominal segments 3-5 is similar to males. Segments 6-10 are similar, but with dark ventrolateral areas less extensive. Segment 1 is pale in young individuals. The posterolateral margin of the ovipositor basal plate is acutely angulate.
Size: Total length: 34-45 mm; abdomen: 28-36 mm; hindwing: 19-25 mm
Similar Species (south-central US): Lyre-tipped Spreadwing (L. unguiculatus) lacks dark marks posterior to the legs, ventrally on the thorax. Spotted Spreadwing (L. congener) has dark spots on the metepimeron which are lacking in Plateau Spreadwing. Common Spreadwing (L. disjunctus) is larger and the dark areas on the thorax are more extensive
Habitat: Still, slow moving waters
Natural History: In our region this species emerges in early January and flies through December. This species prefers laying eggs in rushes well above the water line in irregular vertical rows.
Distribution: Arizona, New Mexico, Oklahoma and Texas as far east as the Texan biotic province, south through Mexico to Costa Rica
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).
