(HOST) One insect in particular seems to embody the ephemeral quality of spring in Vermont – especially if you enjoy fly fishing – and commentator Ted Levin says it’s not the mostquito or the black fly.
(LEVIN) Recently, I stood at the edge of the Post Mills Little League field packing batting helmets, while a small gathering of brown mayflies began landing on my ballplayers. Each was one and-a-half inches long and held transparent wings at right angles to its body, butterflylike. Three long, flowing tail filaments swept up from the rear. They weren’t troubled by our repeated examination of them and may have actually preferred being handled to being buffeted by the wind, which had been strong enough to effect the flight of fly balls.
The mayflies, which had just emerged from Lake Fairlee, the first hatch I’ve seen this spring, belong to a primitive order of insects that evolved before the Age of Dinosaurs. They are Earth’s oldest surviving flying insects and have changed little since the days of the steamy Carboniferous. Mayfly nymphs are gill-breathing creatures that burrow into river and lake bottoms, tilling the mud. Densities of up to 10,000 per square meter convert rivers and lakes into bottom-feeder smor- gasbords, which feed all manner of aquatic life. In preparation for flight, the nymphs had risen to the surface of Lake Fairlee where they were met by squadrons of perch and walleye and trout.
The mayflies that clung to the ballplayers were not adults. They’re subimagos, or subadults, known to flyfisherman as dun. Within 24 hours, the dull colored subimago molts into a mature mayfly, the only insect to molt after its wings are functional.
Dun or adult, when airborne, mayflies attract birds – swifts, swallows, martins, nighthawks, flycatchers, even woodpeckers – which feast on the delicate, soft-bodied insects. Bats, toads, frogs, shrews, dragon- flies and spiders also take a toll. Keeping ahead of the mayfly hords, however, is like beating the enemy in Pac Man; they just keep coming.
One June evening more than 30 years ago, I drove through a swarm of mayflies freshly emerged from the Mississippi River. My windshield wipers could not keep pace, so I pulled into a gas station. Windrows of carcasses, some five and six inches deep, gathered alongside the station, piled against buckets and the wheels of parked cars, covered window sills and decorated spider webs, whose owners prospered from the annual banquet. The “hatch”, I was told by an attendant, was one of the defining events of life along the Mississippi River.
An adult mayfly never eats. Like a battery, it lives off a charge of energy stored as a nymph. Beautiful and ephemeral, adults survive a day or two before their bodies rain on riverine woods, providing a huge pulse of fertilizer. Like water cycling between heaven and earth, mayflies cycle nutrients between water and land. Some towns along the Mississippi River use snow plows and sanding trucks to keep traffic moving across bridges slick with carcasses.
I recently came across a British website, whose owner proclaimed the best brief biography he’d ever read was written for a mayfly. It amounts to: Born. Eat. Mate. Die.
This is Ted Levin of Coyote Hollow in Thetford Center.
Ted Levin is a writer and photographer and winner of the 2004 Burroughs Medal for Nature Writing. He spoke from our studio in Norwich.