Here there be dragons

In this case, these are good dragons that eat many of those annoying mosquitoes over their several-month lifetime. Damselflies and dragonflies belong to a group of insects (Odonata) that are relatively ancient, and their preserved fossil forms from 300 million years ago look much the same as their descendents do today.

Two sets of wings (which can be operated independently of one another) gives them both speed and maneuverability, and like hummingbirds, dragonflies can fly forwards (at 100 body lengths per sec), backwards (3 body lengths per sec), and hover in place. They can dart out from a perch to catch small flying insects at speeds of 60 mph. Like birds, some dragonflies may hunt from a perch, turning their heads to follow potential prey then darting out to catch them, and returning to the perch to consume them. Other species primarily hunt from the air, cruising back and forth across the wetland to chase down those pesky mosquitos.

The most common species I've seen in suburban wetlands are these:

This is a male 12-spotted Skimmer (aptly named), which is easily recognizable from a distance because the white spots contrast sharply with the dark ones. Only males have the bright blue abdomen (females are duller in color). Skimmers perch horizontally while hunting, which enables amateur photographers to get good pictures of them, even though they are only 2 inches long.

This is a Widow Skimmer which hunts from the tips of weeds in open fields, rather than over the water like its 12-spotted cousin. Males defend small territories, but establish new ones each day, which I'm sure adds to their energetic cost of life.

This is a White-faced Meadowhawk, a small (1 inch) dragonfly common in the low vegetation where it perches to hunt. Being so small, they are vulnerable to predation by insectivorous birds, and therefore don't let you get close enough to get a good photo of them. For better pictures of meadowhawks, see photos of another St. Paul-ite at http://ecobirder.blogspot.com/2008/10/carpenter-dragonflies.html

And lastly, a small (1.5 inch) but very distinctive dragonfly that I only saw once out in a prarie field, the Halloween Pennant, so named because of the black and orange markings on the wings. As you can see in the photo, they hunt from the tips of flower or grass stalks.

Some interesting facts about dragonflies:
They spend most of their life in water growing to adult size; they molt (shed skin) 8-17 times, increasing in size with each molt. In northern climates, they may live 8 years as a nymph, but only one summer season as an adult.

The enlarged and clawed lower lip of dragonfly nymphs can shoot out in 1/100 of a second as far as 1/3 of their body length to snare small crustacean prey. In the absence of fish, they are the dominant predator in ponds.

The gills of aquatic dragonfly nymphs are located inside their rectum; they breathe by moving water rapidly in and out of the anus (note: fresh water turtles do this too).

One mating provides a female with enough sperm for her reproductive lifetime. Although mating events may last hours, the transfer of sperm to the female only takes a second. The rest of the time the male is most likely removing the sperm from any previous mating; his penis is highly modified with a brush that scoops up any sperm and ejects it.

Dragonflies have really beautiful, multifaceted eyes that are particularly
good at picking up motion.

To see some really nice HD photos, go here:

To see a slow-motion video of Dragonfly flight (from David Attenborough's "Life in the Undergrowth"), go here: