Why such a war between the sexes? Scientists seeking clues to the answer are finding in dragonflies a bizarre mix of cooperation and conflict, instinct and experience, which may explain not just their odd reproductive habits but also their dazzling diversity of colors and species.
When my grandmother was growing up, dragonflies were known as devil's darning needles and horse stingers, considered an annoyance by some, a danger by others. In many places the insects are still under suspicion, dubbed finger cutter, horse killer, ear stick, and eye pisser. They are poisonous. They will sew together your lips. They will crawl into your ear and penetrate your brain. They will sting you. They will bite you. They will bring you rotten luck, or worse.
"Not so," says Philip Corbet, a biologist from Cornwall in England. "Dragonflies are neither nuisance nor danger—that is, unless you're a mosquito." Or another dragonfly.
Corbet is fixed on a pair of elegant blue-tailed damselflies on the sunny bank of a small lake in Spain—one azure, one ocher, "both from the species Ischnura graellsi, renowned for having females of more than one color," he says, and also, for the male's distinctly "ungallant" behavior. "To secure a copulation, a male will seize a flying female and sometimes even bite her wings at the base."
This pair, however, is locked in an embrace that can only be described as an ersatz heart.
Anyone who has watched dragonflies mating in the bright air has seen a wonder of evolution, Corbet says. Odonates, as they're called, or "toothed ones," have been around for more than 300 million years, which has given them time to figure all the angles on sex. Judged by their longevity and diversity (6,000 species) and the scope of their distribution (every continent except Antarctica), they're one of nature's great reproductive success stories.
Corbet brings his net close to the coupled pair. He keeps the net's shadow low, then whips the net over with a quick flick of the wrist. Such skillful fliers are dragonflies and damselflies that they often make a mockery of such efforts at capture. (The difference between a damsel and dragon, in a nutshell, is that the damsel is small and slender and holds its wings over its back when at rest; the more robust dragonfly holds its wings outspread.) But Corbet is a master. As a child of six, he fell helplessly in love with the insects. Now in his 70s, with two wings of snow-white hair and a full white beard, he is the doyen of dragonflies and author of the "bible" on the subject.
He pulls the male out of the net and turns him upside down to look at his genital organs.