Our Endangered Dragonfly
The nation's only endangered dragonfly is found in just four places in the world — one of them is Northern Michigan. We join an army of odonatologists on their mucky mission to keep the Hines emerald in the land of the living.
Mar 4, 2008 Text by Lynda Twardowski
(page 3 of 5)
The Hines in Vogt's hand was netted during its territorial patrol. Males typically set up a small area to defend, generally only five square feet or so, hovering and darting about to keep other males out, whilst hoping a female Hines zips through. Males pick their patrol zone based in its appeal as a breeding spot for females.
Hines ladies don't linger at breeding sites — they prefer the cover of forest edges and sedges — but when they're ready to breed, they head for small spots filled with a wee bit of cool groundwater. The small depression a boot makes in muck, into which cool groundwater quickly seeps, often makes an opportunistic place for females to deposit their eggs, says Vogt. So males hover over spots like these, waiting for a female to pass by. When she does, the magic happens: The pair copulates, the female oviposits, and a new generation of Hines emerald eggs waits in the muck until hatch time the following May.
After the hunters' cameras stop clicking, Vogt raises his thumb from the Hines' back and stretches his hand flat, launch pad style. The Hines takes the hint and lifts off, eager to get back to business. The hunters raise their nets and disperse, ready to do the same.
The window for getting up close and personal with the Hines emerald is a small one. Adult Hines dragonflies are active only late June through early August, depending on weather conditions. The Hines larvae, a stage that lasts three years before it emerges as an adult dragonfly in its fourth, is active just slightly longer than that — also depending on weather, but complicated slightly by the fact that the larvae spends much of its life underground. It's a challenge that's made the Hines emerald even more fascinating to its fans.
One fan is Dr. Daniel Soluk, an odonatologist from the University of South Dakota, who today, in a mucky, scrubby spot just off the side of M-123 is cracking open the study window a little wider. He's invented a contraption that pumps Hines emerald larvae from their underground burrows, and he's about to demonstrate for the group.
His contraption — a basic bilge pump that's screwed to a piece of plywood and connected to two black Shop-Vac-like hoses — is an exciting advancement, but one made even more remarkable by the strange discovery that it's revealed: Hines larvae don't live in their own underground burrows. They live in the burrows of Cambarus diogenes,
commonly known as the devil crayfish — and a predator of Hines emerald larvae.
Soluk, beads of sweat rolling into his white terry-cloth headband, crouches down under the blazing sun and roots his fingers through the muck. He finds two holes, likely entrances to the same crayfish burrow. Soluk stands up and shouts to a small white fire truck parked on the roadside. On his cue, it revs up like a giant lawnmower, pumping out the water Soluk will use to flood the burrow.