Does the top of the thorax have two thick, parallel, yellow-green stripes?	Does the top of the thorax lack stripes or are they not thick or parallel, and does the top of the abdomen have bright yellow spots?
Plains Clubtail Gomphus externus	Western River Cruiser Macromia magnifica

Written by Mark Lung and Stefan Sommer, 2000
Photos by Dennis Paulson and courtesy of Stefan Sommers, 2001.