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An invasion of swarming, blood-sucking insects

During the summer of 2000, my first summer managing the Wetlands, Pines and Prairie Audubon Sanctuary, now called the Audubon Center of the Red River Valley southeast of Warren, I experienced an unbearable infestation of mosquitoes of the likes I've never seen before or since.

Those valley mosquitoes prevented even the most devout birder from enjoying themselves, including even resident mammals. I observed squirrels, deer, and cottontail rabbits being driven mad as the animals tried in vain to escape by running from one location to another. Even birds, trying to feed from the feeders, were reduced to hurried visits as they, too, felt the wrath of the swarming, blood-sucking insects.

The late Eldor Omdahl, the benefactor of the Audubon Center who died about a year ago at 101 years of age, but then 93, casually commented about that summer's huge number of mosquitoes. He mentioned that he had never seen them worse. In a way, I took solace in his words. If a centenarian like Eldor had never seen mosquitoes as bad, then I should likely live the rest of my days in relative comfort.


Depending on where you live the mosquito population has been strangely sparse this spring and early summer. Most Minnesotans gauge the severity of the insects by drawing comparisons of one year with another. In some areas in some years in northern Minnesota abundant rainfalls can create the perfect environment for mosquitoes to reproduce in great numbers, as was the case for the summer of 2000. Timely rains (or untimely from our point of view), warm temperatures, and plenty of standing, stagnant water everywhere made for a veritable breeding ground for mosquitoes.

There are literally tens of hundreds of different species of mosquitoes inhabiting the globe. Take heart though, they're not all here in Minnesota, albeit you'd never know it. And not all "skeeters" bite either, and of the species that do, only females seek out and bite warm-blooded victims. In contrast, male mosquitoes survive on sugar-rich fluids garnered from plant nectar and other plant juices. But the female, though surviving on the same foods, seeks out blood meals not for her own nourishment, but rather, for the nourishment of her eggs. Protein-packed blood provides her developing eggs with the needed sustenance to grow and mature.

Eggs are laid in the water, mostly in calm water, but some species lay eggs in flowing waters. It takes about two-weeks for adult mosquitoes to emerge from the aquatic forms to their mature and flying existence. Living short lives from one day to weeks, the female's main mission is to mate and seek out blood meals. And she does this in a very unique way.

Because of special receptors (sense organs) located on her mouthparts, female mosquitoes home in on intended victims quite easily. All of us know this to be the case as we step outside and are attacked soon afterwards. Mosquitoes are able to detect us from carbon dioxide that we exhale from our every breath, the lactic acid on our skin, and our body heat. Though we cannot change what we exude from our lungs, we can mask the lactic attractant on our skin by either covering ourselves with clothing or using repellents, which is either directly applied to the skin or on the actual garments.

The bite is made possible by piercing and sucking mouthparts and an anticoagulant that the insect expels to prevent clotting from occurring while garnering its meal. Two to three blood meals may be necessary to lay that first batch of eggs. And once eggs are laid in the water, it doesn't take long for a new population of mosquitoes to join the masses.

Since Minnesota mosquitoes require water for egg depositing and the subsequent life forms prior to adulthood, dry seasons, therefore, produce less of these aquatic-dependent insects. It could be one of the factors contributing to the relative scarcity of mosquitoes in some parts of the region. Up until lately, our months-long drought has lessened the mosquito population in my neck of the woods. However, that is not the case in some parts of Minnesota.

Also, in ponds where fish are present, particularly small fish like minnows, mosquito larvae do not survive very well. But in stagnant, temporary wetlands, pools, and other microhabitats where no predators exist, mosquito larvae flourish. Standing water in farm fields are especially important to mosquito production.

So what's a person to do? For one thing, don't provide places for water to collect, like old tires or containers. Construct or purchase bat houses and install them at suitable locations on your property. Bats do eat mosquitoes, but they also eat many other species of flying insects. Protect yourself when you venture outdoors by wearing clothing that will cover your skin and using insect repellent. Special clothing is now available with repellent infused fabric.

It is critical to protect your skin, because, according to the Minnesota Department of Health, "While mosquito-transmitted disease is not as common in Minnesota as it is in tropical climates, there are several diseases of potential concern to Minnesota residents. Minnesota residents who travel to other countries can return with tropical diseases such as malaria. West Nile virus was found in Minnesota in 2002 and we suspect that this virus will continue to be a public health concern in future years."

Although mosquitoes make up the diets of many creatures of the animal kingdom and many plants depend on some species of mosquitoes for pollination, would we be better off without our so called "true" Minnesota state bird, the mosquito? Many people would agree that we would be better off without them, but with or without the lowly mosquito, this pestering and biting insect is a part of the web of life as we get out and enjoy the great outdoors.

(Klemek is the DNR Area Wildlife Supervisor in Detroit Lakes. You can contact him at