The Common Whitetail Dragonfly is a stocky, medium-sized dragonfly. It is widespread throughout North America and can be seen in all of the Pacific Northwest. It is a species that is easy to recognize by its chalky white coloration that is present on the broad abdomen of the mature males.
The male common whitetail has wide, black bands on its wings, there is a broad band near the wing tip and a small narrow band at the base of the wing. The head, eyes, and thorax of the male are dark brown, and faint pale stripes are visible on each side of the thorax.
The immature males have all the same markings except they lack the white markings on the abdomen and have small white spots that run along the sides.
The face, eyes, and thorax of the female common whitetail are brown, and the thorax has two white stripes on the sides which become yellow at the ends. The female’s abdomen is brown with white or pale yellow spots on each side. The spots form diagonal lines. The wing pattern of the female is completely different from the males, she has three dark spots or patches on each wing.
The common whitetail dragonfly has a long flight season, they fly from early spring to late autumn. This dragonfly feeds on small insects which it captures in flight.
The males are very territorial during the breeding season. An adult male will patrol his territory and drive off all other males he encounters. The success of the male’s defense of his territory usually depends on age, with older, more mature males generally being more successful than young, immature males.
Most males are only able to defend their territories for a few hours per day though, this sometimes leads to more than one male defending the same territories at different times of the day.
The female will visit breeding sites every few days, usually around midday looking for males. after copulation, the female will immediately begin oviposition. The female taps the water with her ovipositor to lay up to 50 eggs with each tap. She may deposit up to 1,000 eggs in total. The male will protect the female during her egg laying by flying just above her.