Image via MN Dragonfly Society
The St. Croix River is a special place for dragonflies. The unique insects are abundant, and one is even named after the river.
A public event this Saturday, January 3rd, in Marine on St. Croix will share knowledge about dragonflies and damselflies in Minnesota, and efforts to ensure their long-term conservation.
The Minnesota Dragonfly Society‘s first-ever annual meeting should have something for everyone. Hosted at Warner Nature Center, programs include “Dragonflies in the Classroom,” a member photo slideshow, a presentation about a population survey near Red Lake in northern Minnesota, an overview of 2014 dragonfly research, and dragonfly photography tips and tricks. Scott King Red Dragonfly Press will read his dragonfly poetry between programs, and there will craft activities for kids.
The event runs from 1 to 5 p.m., Saturday, January 3rd. It is free and open to the public. Warner Nature Center is located at 15375 Norell Ave N, Marine on Saint Croix, MN. More information is available on the society’s website.
The St. Croix is abundant in the fast-moving, clear waters that many species prefer. There are dozen of species that live in the river and its tributaries.
The St. Croix River’s very own dragonfly is Ophiogomphus edmundo, or St. Croix Snaketail. It was first identified just 25 years ago, a discovery that was later written about in the New York Times:
So in November, he recalled, while wading in the frigid river ”in water deep enough for me to barely stand in, which is unusual for dragonfly larvae, I came up with half a dozen dormant larvae” that looked just like the skins he’d collected the summer before. Back in Madison, Mr. Smith placed the larvae in a large cold aquarium and gradually warmed the water and increased the exposure to light to break the larval dormancy. Finally, in February, the larvae climbed out of the water, shed their final skin and hatched into magnificent clear-winged adults with bulging, bright green eyes, emerald thorax and black abdomen with bright yellow markings.
”Right away I knew it was a new species,” he said. But to be absolutely sure he could describe it fully and accurately, he returned to the river the next summer to snag some of the naturally emerging adults, which he and Mr. Vogt named Ophiogomphus (the genus for snaketail) susbehcha (the Lakota Sioux word for dragonfly), now known as the St. Croix snaketail.
The species has been listed by the state of Minnesota as a “species of concern,” due to its low numbers. A 2012 Star Tribune story discussed the possibility that it could be designated the more protected “threatened” status.
“That suggests that the St. Croix snaketail, or its kind, were at one time largely distributed, but they’ve largely disappeared as a result of human activity,” species discoverer Bill Smith said.
The Minnesota Department of Natural Resources says the few rivers where it is found (it has since been discovered in Pennsylvania and Maryland), separated by thousands of miles, indicates it could easily disappear from the St. Croix, too:
This type of distribution pattern is very typical of sensitive species, which are affected by habitat disturbance and fragmentation. Established St. Croix snaketail populations have been found along the upper St. Croix River on the Wisconsin/Minnesota border, and may also be present along its tributaries. In addition to its rarity, the species merits listing because of its apparent need for high water quality and its sensitivity to pollution, siltation, and reduced levels of dissolved oxygen. The St. Croix snaketail was listed as a special concern species in Minnesota in 1996.
As educator Ami Thompson wrote in a St. Croix 360 post a year ago, looking for and identifying dragonflies can be a lot like birdwatching, and is growing in popularity. But identifying the insects, which move fast and often have miniscule differences, can take an expert. The event this weekend should be a good time to meet those experts and learn from them.
Comment