Stalking prehistoric predators
UPPER SIOUX AGENCY STATE PARK -- We know our mosquitoes too well in Minnesota, but we know very little about the winged insects that love to dine on them.
There may be as many as 140 different dragonfly and damselfly species in Minnesota, according to the Department of Natural Resources.
We know little about where the different species can be found, although it would help us a great deal to know. Each species has its own special habitat requirements. They can serve as indicator species for assessing the water quality of the wetlands, rivers and lakes they depend on, according to Terri Dinesen, manager of the Upper Sioux Agency State Park.
That's why Dinesen and a group of volunteers joined Dianne Rowse, with the Minnesota Odonata Survey Project, to stalk the park's dragonflies and damselflies on Aug. 8.
The Minnesota Odonata Survey Project is training volunteers across the state to catch, identify and preserve dragonflies and damselflies so that we can increase our knowledge of where the insects are distributed.
As Dinesen and the volunteers quickly learned, it's easier said than done. Dragonflies and damselflies are very quick of wing and thanks to composite eyes, very alert to those who would catch them.
But just for the trying, the volunteers were able to catch (and document) the existence of eight different species not previously identified in Yellow Medicine County. This is a record sure to be broke again and again.
Until the volunteers went out, only four species had been documented in the county, and no one is sure who did it, said Dinesen.
That's how limited our knowledge is about these insects, although that might change as people discover how fascinating they are. Sure, most of us appreciate dragonflies and damselflies for the beautiful, electrifying colors many sport, and the aeronautical skills they demonstrate.
But few of us know the amazing stories of these creatures. They are prehistoric, going back to the age of the dinosaurs. (One ancient species of dragonfly had a 30-inch wing span and 18-inch long body.)
Today's versions are described as efficient, toothy predators who have adapted to a cooler and less oxygen-rich world. They are tropical insects. The species making Minnesota their home have found ways to adapt. Most spend their pre-adult life underwater in larval stages, surviving winter under a roof of ice.
Some species take a few years to develop into adulthood in our cool waters, according to the Odonata Survey Project. One species may take as long as seven years.
Others just scram when the cold comes. Common Green Darters migrate in large swarms to the Gulf Coast where they lay their eggs and die. The eggs hatch and mature quickly so that the young, Green Darters can begin their flight back to Minnesota in early spring.
They come here to gobble down mosquitoes and gnats and other flying insects, but pay a price. Purple martins love to dine on them, as do frogs. In their pre-adult stages underwater, fish and other aquatic species seek them out as well.
These days, a butterfly net at the Upper Sioux State Park stalks them as well. Since the outing last month with Rowse, Dinesen has become fascinated by these creatures and eager to identify which species make their home in the park.
To learn more about the Odonata Survey Project and these insects, check out: http://www.mndragonfly.org/.