Spring 2004

By Craig Vetter

It's spring, and Chicago Wilderness — in bloom again—is begging to be explored. But warm weather also brings mosquitoes. Here, the author prepares for them, and finds a little tolerance in the maxim, "Know thine enemy."

Just because the mosquito is the most dangerous killer on the planet, just because there are about 40,000 of them to every human being on earth, just because they inhabit nearly every corner of the earth including the Arctic, just because there are 60 to 70 species in Illinois, and just because nearly everyone who goes outside this summer is likely to get bit, doesn't necessarily mean they're all bad.

Mosquito larvae and adults make healthy meals for fish, bats, birds, shrimp, frogs, crabs, toads, beetles, and spiders, not to mention us when we occasionally breathe them in at the summer picnic. And though anything that comes into this life looking for a blood meal brings a lot of negative baggage along, not all mosquitoes are dangerous bloodsuckers. In fact, here in Chicago, there are only three genera that feed on us or our pets and transmit disease while they're doing it. So rather than pesticiding, zapping, and slapping every last mosquito we can get our hands on, including the innocent, maybe we ought to try to be a little more discerning in our fear and disgust of these hardworking, wildly successful little buggers, take a little mosquito Zen into our backyards this summer, and try to learn how to identify the potentially lethal from the merely annoying in that moment between the landing and the slap.

Well, I've tried, and it's been both frightening and enlightening. I started with the Web, where there are just about as many mosquito sites as there are mosquitoes. Many of them are abuzz with basic mosquito facts:

They say there are trillions of them (although I think we have to imagine that whoever is counting isn't finished yet).

All of them need water to hatch.

Male mosquitoes do not take blood meals. (Thank you, gentlemen.)

The lifespan for most female mosquitoes is two to four months, while many males last no longer than a week (they often die soon after their usefulness in breeding is over). Some mosquitoes can overwinter and come out thirsty for a second season.

Females can go through two to four cycles of blood feeding and egg laying. They produce as many as 3,000 eggs that grow up to adulthood as fast as four to six days.

Mosquito is Spanish for "little fly."

Beyond that good news, the Web sites tend to veer into highly technical discussions of species and genera that contain more Latin words than all the works of Cicero and Virgil together. So I called Richard Lampman, a jovial Ph.D. in entomology who works for the Illinois Natural History Survey, to see if I couldn't get some translation that might help me ID one mosquito from another.

"The identification of species and genera is tricky," he said, "because taxonomists argue endlessly over the classification of animals, which keeps changing our tremendously expensive taxonomy books. A guy called me 20 minutes ago and asked for a way to separate a particular two species and I said, 'Well, you do it by male genitalia, which won't help you with the females and the larva.' He said, 'What good is that?' and I said, 'Well, I don't know.'"

What if we just talk about Chicago mosquitoes, I suggested: the dangerous ones and those that are just a welt-raising bother. And maybe some way to identify them without pulling their pants down.

"Most of the mosquitoes in the Chicago area are not dangerous," he said. "Aedes vexans, the inland floodwater mosquito, is what you're going to see the most. It's a nuisance to humans but can carry dog heartworm. It's a small, dull gray mosquito with scales on the abdomen that look like a cursive small w. They tend to be out biting around dusk. Anopheles quadrimaculatus, which are not in great numbers in the city, are mostly found around permanent pools of water, swampy land like you have in south Chicago. It has a long, cigar-shaped body, spots on its wings, and feeds at night. And Psorophora columbiae is thick and robust, with colored scales above (instead of below) its abdominal segments. You can find them around temporary water, such as grassy ditches of farms and pastures, as well as woodland pools, but they can fly long distances. They bite at night, too."

The Usual Suspects: A Field Guide
Small; dull gray. Scales on top of abdomen look like a cursive small "w." Thin stripes at leg joints.		Long, cigar-shaped body; spots on its wings. Has long proboscis and long maxillary palps. Sits with its head down and butt up.		Dirty brown with blunt abdomen. Sits flat and raises its back legs when it bites.

As for the dangerous characters, he said, "Culex pipiens is the number-one West Nile and St. Louis encephalitis carrier. They like still, polluted water that you might find in old tires or around flowerpots. It's easy to identify by its dirty brown color, blunt abdomen  and the way it rests on you to bite. It sits flat and raises its back legs. Ochlerotatus triseriatus, 'tree-hole mosquitoes,' can carry Lacrosse encephalitis, and feed any time you enter their domain. They live in woods and neighborhoods with older trees, and you can tell them by their pointed abdomen. I should add that Anopheles can transmit malaria but rarely does around here. They sit with their heads down and their butts up, and have a long proboscis and long maxillary palps..."

I stopped him at the palps. We'd talked awhile and I'd gone over my head early in the fog that had one species becoming another during squabbles over very small and otherwise private mosquito parts.

"Do you ID before you slap?" I asked him.

"Well," he said, "as entomologists out collecting, ours is not to slap. We use a modified Dustbuster to pick them up and bring them back to the lab. Otherwise, I'll wear repellent."

"Why not just slap them all and let God sort 'em out?" I asked. "There aren't any really good mosquitoes are there? I mean, nobody keeps them as pets."

"Actually, there are some that are pretty neat," he said. "Like Toxorhynchites septentrionalis. It's one of the largest mosquitoes I've every seen, about the size of a fairly large wasp. It takes nectar only, no blood, and its larvae feed on other mosquito larvae. They're rare in Chicago because they like a more southern, tropical climate."

As we finished our conversation, I asked him if he knew any mosquito jokes, and he did, more than a few. As it turned out, one joke was the most straightforward ID suggestion I got in all my research.

"You know how to tell a tough mosquito?" he said. "You slap it, it slaps you back."

I have yet to meet that mosquito, and until I do I'm not going to worry enough to let mosquitoes ruin my summer. They never have liked me much anyway — which pretty much makes us even.