Pachydiplax longipennis is the sole member of their monotypic genus of skimmers (Libellulidae). It is a medium sized dragonfly (total length 35-42mm), and both males and females develop a heavy pruinosity, although it is heavier in the males. The heavy pruinosity doesn’t quite obscure the green striped black thorax, or the black tipped abdomen. And you can always see the white face, and green eyes. They also have amber patches at their wing bases.
Blue Dashers can be very abundant in early summer, especially at shallow, weedy lakes and ponds. Their larvae have a higher than normal tolerance for pollution and low oxygen levels. They are perchers , who like being right above the water, and they do not perch on the ground like Western Pondhawks ( Erythemis collocata), which is our only other species of small dragonflies with pruinose blue males and green females. They are fairly easy to differentiate because Western Pondhawks have a green face and unmarked thorax, as opposed to the white face and green striped black thorax of Blue Dashers.
They can be found region wide, and fly from mid May into October.
Pachy means ‘thick’ in Greek, and a diplax was a cloak, which I assume is a reference to the thick coating of pruinosity for which this species is known. The species epithet longipennis means ‘long wings’ in Latin, which is only applicable to the females, whose short abdomen makes them appear to have long wings.
Size- 35-42mm total length
Habitat- Slow or still water with abundant vegetation
Range- Region wide
Eats- Small flying insects
Flight Season- May to October