NEW BRUNSWICK, N.J. — Any old pond will do. Michael L. May set out one recent Wednesday morning from his cramped office at the Rutgers University entomology building to collect a few dragonflies The road to a more pristine lagoon in a county park was closed, so Dr. May pulled off a highway two miles from campus and parked alongside a triangular pond lined with tall weeds and poison ivy and wild hibiscus serving up white shuttlecock flowers. With the traffic on U.S. Route 1 whizzing off in the distance, Dr. May, a bushy-bearded Florida native who just turned 65, grabbed his net and shuffled down the bank until his sneakers sank in the mud.
The pond was abuzz with activity. A green darner patrolled the surface like a fighter pilot. Bluets posed primly on slender reeds, and three stocky little Eastern amberwings chased one another around choice perches.
“There’s a pair copulating on the bamboo.” Dr. May pointed to two Eastern pondhawk dragonflies — green-and-black female and blue-dusted male — shimmering in the sunlight in a familiar heart shape.
Dr. May turned his attention and his net elsewhere, poised, and struck. Swish-swish, and a thick, blue-black helmet-headed creature — named, in the fanciful way of the dragonfly world, a slaty skimmer — danced in the fabric.
“This is the one I was hoping for,” he said. “It’s a common enough thing, but it has a fairly rococo penis.”
Dr. May — main author of the modern revision of the standard identification manual “Dragonflies of North America,” editor of the International Journal of Odonatology, describer and namer of six species of damselfly and dragonfly, expert at insect energetics — is spending his last year at Rutgers starting a project that should keep him busy well into retirement: understanding the mechanics of dragonfly sex.
Dragonflies have dizzyingly complicated and varied reproductive organs. Their penises are multijointed contraptions resembling high-tech prosthetic legs accessorized with horns, brushes, hooks, grabbers, spreaders and other implements designed to effect both the deposit and the retrieval of sperm, among other things. Females are comparably intricate, if not complementarily so — as the evolutionary arms race would have it, Madame Dragonfly has designed herself to thwart her mate’s ability to remove his rivals’ sperm.
The general requirements of dragonfly sex are elaborate enough: Before mating, the male contorts itself to transfer sperm from its manufacturing site at the end of its abdomen into a slit in the penis, which is mounted toward the front half of its body, just behind the thorax. When love comes calling, the male uses appendages at its tail end to grab the female at the back of the head. She, in turn, wheels her abdominal tip forward to allow penetration.
But exactly how the parts fit together in a particular species, and what specific tasks they perform, is hard to study: The mating process is incompatible with vivisection. In the dragonflies’ skinnier cousins the damselflies, which copulate for up to an hour, researchers have learned quite a bit by freeze-framing the action (that is, killing the participants) at various stages of the sex act. Most dragonflies, though, couple for only a few seconds.
So this past summer, Dr. May headed out to still waters in New Jersey and elsewhere, collecting specimens, bringing them back to his campus lab, killing them, excising their genitals, squeezing them with forceps to inflate them into simulated tumescence and examining them in great detail.
“I’m trying to get us to the point to where we’re a little less confused as to the function and the historical evolution,” he said.
He is hoping to figure out the workings of enough species to recognize broader patterns of function and design, even when male and female parts do not seem to completely correspond.
“Whether that will lead to a Grand Unified Theory of Odonata Penises, I honestly don’t know,” he wrote in a later e-mail. “It may be that different species have solved the same problem many different ways, but to me that’s also interesting to know.”
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