Common Green Darner Dragonfly

One of North America’s most common and widespread dragonflies (6) (7), the common green darner (Anax junius) is a large insect with a bright green head and thorax and a contrasting blue abdomen. In the female and immature common green darner, the abdomen is dull green, reddish or brown, and in all individuals there is a black line running down its upper surface (2) (3) (4) (5) (6). The name ‘darner’ is thought to derive from the long, narrow abdomen typical of dragonflies in the Aeshnidae family, which somewhat resembles the shape of a darning needle.

http://www.arkive.org/common-green-darner/anax-junius/