Bees and butterflies are the poster insects of our time — this is good; they need our help — but there is another amazing garden creature that enriches our world and gives a flash of color and life to the languid days of late summer.
Dragonflies seem masters of their universe — powerful, aerobatic, predatory in an endearing way. I speak as an impartial human, not a gnat.
Dragonflies and the related (and seemingly gentler) damselflies are also beautiful. This is not obvious, because to perceive this you have to wait for a dragonfly to be still and to spend some time being still yourself.
What you might see is the common whitetail, an abundant dragonfly with a dusky blue-white abdomen and black bands on its otherwise clear wings; the common green darner, a three-inch-long dragon with black and green stripes on its thorax and a blue-flecked abdomen; or the eastern amberwing, just an inch long and with wings the color of smoky cellophane.
But it is not just the marvelous colors and markings, but the form, a primeval beauty that nature got right from the start (as in 300 million years ago). The four wings extend out from a muscle-bound thorax, signaling, even when still, a potent mastery of the air. The wings are long and veined — the veins act as bracing — so the effect is like looking at stained glass, with a mosaic of panes and tracery of leading.
Adult dragonflies aren’t much good at walking (the legs capture prey), but the wings turn them into aerial acrobats. Photographer Pieter van Dokkum writes in his new picture book, “Dragonflies,” “They have mastery of their environment that is unique in the animal kingdom: they can fly upside down, stop, and change direction in the blink of an eye, hover and suddenly accelerate to speeds of up to thirty miles per hour.”
One ubiquitous species, the wandering glider, has turned itself into the albatross of the arthropod world by sticking out its wings, working the currents and soaring for thousands of miles. “They ride the winds,” says Oliver Flint, the Smithsonian’s curator emeritus of Neuroptera (net-winged insects). “They appear on oceangoing vessels, far out at sea.”
And then there are the peepers. The compound eyes are not only colorful in themselves, they are also phenomenal, occupying almost the whole head. You won’t creep up on a dragonfly, but if you scare one off, wait a while, van Dokkum says, and it will probably return for your examination and enjoyment.
Dragonflies are beneficial to us in that they eat mosquitoes, both in the air as adults and as ferocious little nymphs in ponds, but their great value simply is the way they enrich our world. A backyard pond will draw them — they need freshwater for their life cycle — but often you can regard them in great hunting packs over dry land. “It’s common to see them in fields or along old roads,” Flint says. In early fall, I can sit in my little community garden plot and see a dozen or so big dragonflies moving back and forth over the open gardens. At first I thought they were hummingbirds, they were so large, but study showed them to be dragonflies, probably common green darners.
There are approximately 120 species of dragonflies and damselflies in our region. The two places I know with the greatest array of these insects are Kenilworth Aquatic Gardens in Northeast Washington and Huntley Meadows Park in Fairfax County.
Van Dokkum has been photographing dragonflies for years, but his main gig, so to speak, is astronomy; he chairs the astronomy department at Yale University. He observes nature at both poles of its scale, at the microcosm of the insect world and the vast expanses of the cosmos. Both are mysterious worlds that reveal their secrets slowly, but van Dokkum has been inspired by one to study the other.
Fascinated by the dragonfly’s compound optics, he has collaborated with other astronomers to create a telescope consisting of a cluster of 10 telephoto camera lenses. Called the Dragonfly Telephoto Array, it has proved highly effective at finding new low-light galaxies, specifically seven dwarf galaxies in the field of a large spiral galaxy known as M101. The images of each of the 400mm lenses are assembled into a single picture of galaxies that were too diffuse to find with conventional telescopes.
This artificial dragonfly eye differs from the real McCoy in a couple of regards.
Each of the camera lenses is focused on a common point, whereas each of the dragonfly’s is directed at a slightly different angle, “with all the segments together creating a nearly 360-degree view,” van Dokkum said. Taking a leaf straight out of the dragonfly’s book, he is thinking of assembling a 50-lens array where clusters of 10 would look at five adjacent points in the heavens.
The other big difference, he points out, is that a dragonfly’s eye has as many as 30,000 segments. Try replicating that with telephoto lenses. By my calculations you would spend $300 million on the optics alone. (I’d ask for free shipping.)
Van Dokkum is struck that dragonflies have been on Earth for a period of time that is mind-boggling even by astronomic standards. And yet the life span of each individual adult is a matter of weeks or months. By the autumn, their bodies are faded and their wings ragged. “You can see them aging, and with shredded wings they’re still able to fly,” he said.
In other words, their spirit transcends their senescence, and you can’t help thinking that something so primitive can teach us so much.