wordswild's Identifications

In Insects of Western North America, 9. The dragonflies and damselflies (Odonata) of Colorado:
An updated annotated checklist, Bill and Inex Prather state for Ishnura damula Clavert (Plains Forktail)
“This species is usually the most commonly collected, photographed, and observed species throughout most of the state to about 1,800 m.a.s.l. and less commonly at higher elevations. We have one specimen from greater than 3.100 m.a.s.l. in Boulder County. We have examined no records from north of the Colorado River Valley in western Colorado.”

For Ischnura cervula Selys (Pacific Forktail) they state, “This species occurs in western Colorado from lentic habitats in the Colorado, Rio Blanco, Green, and Yampa river drainages to about 2,200 m.a.s.l. We know of no verifiable records from east of the Continental Divide in Colorado. All specimens in the CSUC from eastern Colarado labeled Ischmura cervula: are actually I. damula. Although both species have been found in the Colorado River Valley, we have not found any location where they are sympatric.”

These two species are the only Colorado forktails that show four blue dots on the top of the male’s black thorax. They cannot be separated without careful examination of their terminal appendage. However, since I. cervula has not been recorded on Colorado’s eastern slope, I think it is safe to call records from there L.