The Blue Dasher, A Dragonfly That Zings
I am sure I saw a cartoon with an animated dragonfly as a fighter pilot. It must have been one of those “old-timey” Popeye era ones. Since then, I have been fascinated by dragonflies.
I don’t know if it is their wickedly cool body design or their piloting skills. Probably, it’s both. Just look at some of these photos.
This is a Blue Dasher (Pachydiplax longipennis). Apparently, “longipennis” means “long-winged”. Thank goodness. The Blue Dasher is also called the Blue Pirate. This species is abundant across much of the United States.
I spotted many Blue Dashers around a body of standing water (a pond in this case) with some vegetation. If water doesn’t have some vegetation, Blue Dashers are unlikely to be there.
The males and the females look quite different. It is the males who have the black-tipped blue abdomens, white faces and metallic green eyes. Females and immature males have brown thoraxes with yellow stripes and reddish-brown eyes.
Sometimes the markings on the wings are useful in identifying species.
The intricate delicate wings are engineering marvels. Not only can they beat up and down, but all four wings can move independently. The wings can also rotate like an airplane propeller. Dragonflies can fly up, down, backwards, forwards and hover in midair.
The males have a favorite perch which serves as their headquarters. From this perch, the males periodically fly over the pond and chase other males. The males spend much of their time chasing each other and displaying their blue abdomens.
This male (known by the blue color of the abdomen) is perching on a plant stalk overlooking a pond. Blue Dashers display behavior called perching. Perchers, in the dragonfly world, perch horizontally on shoreline shrubs and vegetation, many times high up from the ground. Perchers make brief flights at low (under six feet) heights over their territory. Which is exactly what this dragonfly did. Other dragonflies are “fliers” which spend long periods flying, not perching.
This is a dragonfly nymph. Dragonflies have a three-part life cycle of egg, larva (nymph) and adult. They go through metamorphosis much like other insects. When a dragonfly nymph is fully growth it climbs up a stalk, out of the water and the adult form emerges.
Fun Facts about Dragonfly Nymphs
Dragonflies breathe through gills in their rectum. The rear end of a dragonfly functions as an extraction machine which separates oxygen from the water so the dragonfly can breathe. I think the expelling of the water is what also gives the rectum functions as jet propulsion under water. The dragonfly must shoot water out of the rectum which creates the jet propulsion under water. The rectum is also the end of the digestive track and performs the usually waste disposal actions. In the book Dragonflies and Damselflies of the East, Dennis Paulson calls the nymph rectum a “multipurpose organ” and a “miraculous rectum”.
The Blue Dasher is one of the species of dragonflies that appears to migrate. I say appears to migrate because large populations of Blue Dashers are seen in midsummer along the Atlantic Coast. It appears no one knows where they go.
I spent an hour watching dragonfly behavior at the pond. It was hot but I was fascinated. Now that I know one species, I will be on the lookout for more.
Books on Dragonflies on My Bookshelf
Dragonflies and Damselflies of the East (Princeton Field Guides) by Dennis Paulson. Princeton: Princeton University Press, 2011.
Dragonflies and Damselflies of the West (Princeton Field Guides) by Dennis Paulson. Princeton University Press, 2009.
Stokes Beginner’s Guide to Dragonflies by Blair Nikula, Jacke Sones, and Donald and Lillian Stokes, covers over 100 common species of dragonflies and damselflies. Boston: Little, Brown and Company, 2002.
Dragonflies & Damselflies: An Introduction to Familiar, Widespread North American Species (North American Nature Guides) by James Kavanagh. Waterford Press, 2000.