Pachydiplax longipennis Female
The blue dasher (Pachydiplax longipennis) is a dragonfly of the skimmer family. It is common and widely distributed in the United States
Mature males develop a bluish-white pruinescence on the back of the abdomen and, in western individuals, on the thorax. They display this pruinescence to other males as a threat while defending territories at the edge of the water.
Females are paired with yellow stripes on the dorsal side of the first 8 abdominal segments, the part of the body that lies between the thorax and the pelvis and encloses the stomach, intestines, liver, spleen, and pancreas; more commonly known as the belly. Females are also reported to turn blue, but at a slower rate then the males.