By Jake Rossen
By Jesse Marx
By Michelle LeBow
By Alleen Brown
By Maggie LaMaack
By CP Staff
By Jesse Marx
Predators--nature's own mosquito control--aren't as effective as legend has it, Pennuto notes: Purple martins and bats will eat mosquitoes when it's convenient, but they won't devour their weight in skeeters, as the tale goes. Dragonflies and praying mantises will eat mosquitoes, but not enough to make a significant dent.
The corncob granules won't kill all the mosquitoes either: According to MMCD studies, treating a wetland with Bti will eliminate between 78 and 89 percent of the larvae living in it. But the bacteria become ineffective in about a week, and new eggs are constantly hatching--especially as the weather gets warmer and the water comes alive with the larvae of Aedes vexans. This species, which, according to the MMCD, accounts for eight out of ten mosquitoes found on humans in Minnesota, has a shorter lifespan than its spring-hatching relative, but it makes up for that by reproducing frenetically.
Which is why Pennuto will be visiting this particular wetland regularly, all summer long--even when the swarms get thick. The MMCD offers bug spray to employees, but, says Pennuto with a nonchalant shoulder shrug, "I have yet to be bothered enough to use it." It's only when he goes home to Wright County, outside the District's jurisdiction, that he faces the true wrath of the skeeter: "There have been times," he admits, "when I have had to go into the house."
Roger Moon keeps his mosquitoes in the house--or rather, in his office at the University of Minnesota, where he's served as a professor of entomology for the past 20 years. A bespectacled, fit man with a magician's quick-moving hands, he rummages rapidly through the drawers that hold the University's insect collection. It takes two minutes, tops, to find the box containing what he considers the most beautiful mosquito in Minnesota. Moon buzzes about the lab, retrieving a microscope that looks old enough to have been used for Salk's polio vaccine, adjusting a light, and offering a quick refresher course in insect handling: "You see how I'm using my pinky to hold this pin? That's the best way to hold samples," he says, gingerly placing a dried specimen of Uranotaenia sapphirina under the lens.
The mosquito is stunning indeed. Spreading out from the hairy body are a pair of wings so delicate, iridescent, and sparkling with what looks like fairy dust, they should be on a fourth grader's elf costume. But the proboscis--the mouth--is enormous, hideous. Moon puts his hands up to his face and uses his fingers to mimic its action: "You might think the proboscis would be rigid like a hypodermic needle, but it saws and wiggles around like a noodle until it finds the capillary," he explains, fingers weaving like the tentacles of a sea urchin. "And mosquitoes are quite pharmaceutically complex: Their saliva--which is what makes you itch--deadens your skin, making it less likely that they'll be slapped. The saliva also keeps your blood from clotting--otherwise it's like a milkshake that's too thick. You know..." he sucks in his cheeks as if sucking on a straw.
Then he sheds the mosquito persona and becomes the professor again. "We entomologists like to beat our chests about why insects are great," he explains. "The fact that there are so many is a measure of their success--insects make up well over half of all known species. They're small, they fly, they're fast. And they react more quickly to chemicals. One molecule of female sex pheromone can affect a male moth. We don't think vertebrates are that good at sensing a female."
Among the insect species most adept at reproduction are flies--Moon's "first love," he admits, ever since he wrote his doctoral dissertation on insects and cow pies. "Houseflies make a living exploiting the landscape--putting out lots of eggs," he explains. "The mosquito Aedes vexans does the same thing. It makes lots of eggs, spreads 'em far, and then--I'm giving it human characteristics here--prays to God for a thunderstorm."
What happens after the thunderstorm is one of the keys to insects' evolutionary success, says Moon. Some 95 percent of them go through a complete metamorphosis--eggs turn into larvae, which become pupae, from which emerge adults. "They split the environment into two habitats," Moon explains, "and so they're not fighting their kids for food." Of course, he grins, "it also means that we're fighting them on two fronts."
And we fight them, Moon explains, because we learned to over tens of thousands of years. "That fly in your chicken-noodle--before it landed in your bowl, it probably came from rotting or organic debris, road kill, results of defecation in the woods, the latrine next to the camp. Chances are pretty good that it will have bacteria on it from fecal matter. When I see the fly in my soup, I'm not saying, 'God, I'm going to get diarrhea.' But our ancestors survived better when they removed insects from their environment. At the most basic level, eliminating that fly reduces annoyance, but at a higher level, it could also extend life span."
Evolution, Moon adds, even has produced what he calls the "ish scale," a gradated reaction to various insects. "Butterflies and ladybugs go low on the ish scale--the end labeled 'not repulsive.' Anything with a stinger or a potential to bite---yellowjacket, hornets, mosquitoes--will be high on the ish scale; so will ants and houseflies. Bees might jump around the midpoint area because people like bees, but there's a fear that goes with them."