Blue Dasher (Pachydiplax longipennis)
Detailing the physical features, habits, territorial reach and other identifying qualities of the Blue Dasher.
Updated: 2/8/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
The fast and bright Blue Dasher is one of the most commonly sighted and enjoyed dragonflies in all of North America.
Blue Dashers are one of the most abundant dragonflies in the U.S. and can be found near slow moving water sources, marshes and ponds. Adults have four wings with two noticeable dark streaks in them. Adult males have a chalky, blue color from head to abdomen that ends with a black tip. Their heads contain their large eyes which take on a metallic sheen in certain lighting. The female coloring differs from the male. Her abdomen is black with yellow stripes along the sides and top. Her wings do not contain the aforementioned streaks and their abdomens are stubbier. The thorax has yellowish-green striping not seen on adult males. Juvenile Blue Dashers are not blue yet. They have green and yellow stripes on the thorax and yellow dashes along the side of the abdomen, much like adult females.
Males are often seen around water's edge, protecting their territory from other males. They will flash their blue abdomens as a warning to each other. Females usually perch on vegetation and only approach the water when they are ready to mate. Both genders stick their abdomens upright in the air when perched, as if on alert, and they snap their wings closed after settling down. Like other dragonflies, the ecologically beneficial Blue Dasher contributes to pest control by consuming hundreds of smaller insects each day.