In the heat of summer in 1885, at Fort Abraham Lincoln, on the west bank of the Missouri River, Captain Macauley saw something he had never seen before.
The river had spawned millions of mosquitoes and their bites were so bad that Captain Macauley could only remain outdoors if he wore heavy riding boots, “thick trousers, leather gauntlets,” a head-net, and a neckerchief tucked between his hat and shirt-collar.
But the day came when the mosquitoes disappeared “as if by magic.” For out of the same river that spewed forth mosquitoes arose a species of dragonflies, of rather large size that “came in droves and cleared the place out.”
These dragonflies were the biggest dragonflies Captain Macauley had ever seen. “They had four wings, six legs, were about two inches long,” and were dark brown. The wings had a faint emerald-green-tinge.
Captain Macauley was curious how they caught their food, so he observed a half-dozen dragonflies as they flew about in a kind of an “irregular skirmish line.”
What he saw amazed him. The dragonfly wings shimmered and gleamed in the warm sunlight. These “mosquito hawks” were darting, flitting, swooping, zipping in-and-out – maneuvering to devour mosquitoes.
At times hovering, at times moving swiftly sideways at bursts up to 29 feet per second, the dragonflies would use their legs as a basket to capture insects. They would gobble the mosquitoes while flying.
Each dragonfly had compound eyes, resembling beads, covering most of its head, capable of spying its prey 18 feet away, and catching mosquitoes before the insects knew what hit them.
It was on this date, in 1890, that a newspaper story made mention of Captain Carter Nelson Berkeley Macauley of the U.S. Army and his experience “among the dragonflies and mosquitoes of the Upper Missouri” country.
Captain Macauley served as a surgeon at Fort Lincoln for only a couple of years, but he long remembered the summer when excessive rainfall brought forth mosquito clouds from the river bottoms and how airborne dragonflies ate mosquitoes, as their “favorite food.” Macauley was astonished, as we are today, by dragonflies, who swept through the humid air on “iridescent wings,” gliding up and down, as “mosquito hawks on the western plains.”
Dakota Datebook written by Dr. Steve Hoffbeck, MSUM History Department
Sources:
“Dragon-Flies vs. Mosquitoes,” The [Nashville, TN] Tennessean, August 19, 1890, p. 2.
C.N.B. Macauley (1859-1896), “Dragon Flies as Mosquito Hawks on the Western Plains,” in Robert H. Lamborn, Dragon Flies vs. Mosquitoes (New York: D. Appleton and Company, 1890), p. 131-134.
“To Scare Mosquitoes,” Williston Graphic, September 18, 1902, p. 7.
“Dragonflies and Damselflies in Minnesota,” Minnesota D.N.R., https://www.dnr.state.mn.us/eco/nongame/projects/dragonflies.html, accessed on July 12, 2019.
