About Zygonyx iris Selys, 1869
This species of dragonfly is dark metallic blue with brown eyes. Its thorax has a broad yellow humeral stripe. The abdomen is black, with the sides of segments 1 through 3 broadly yellow. A yellow mid-dorsal carina runs from segment 1 to segment 6, and there is a large yellow spot on segment 7. Females are similar in appearance to males. This dragonfly breeds in swift, rocky streams. Its larvae are adapted to cling to rocks. Females lay eggs in first order streams during summer. In their late instar stages, larvae apparently migrate from first order streams to second or third order streams, where they emerge as adults. Males are commonly found flying over brooks and streams. They tirelessly fly back and forth across a set route along hill streams, and rarely perch. Sometimes, tandem pairs can be seen flying above torrents, with the female dipping her abdomen periodically to lay eggs.
