Zygonyx iris,[2] the emerald cascader[3] or iridescent stream glider,[4] is a species of dragonfly in the family Libellulidae.

[1][4] It is a dark metallic blue dragonfly with brown eyes.

Apparently, the larva migrates to second or third order streams during their late instars from where they emerge.

They tirelessly fly back and forth across a beat along a hill stream and rarely perch.

Sometimes, pairs in tandem can be seen flying above torrents; the female dipping her abdomen periodically to lay eggs[8][7][4]