Thinking like a mosquito

What does a mosquito want? Just a nice meal, on you, and a bit of water to lay eggs in. So those are the things members of Pinellas County Mosquito Control's swat team have on their minds.

By JEFF KLINKENBERG

© St. Petersburg Times,
published August 24, 2001

[Times photos: Bill Serne] In a setting that looks like mosquito heaven, Henry “Hank” Marquardt of Pinellas County Mosquito Control scopes out a neighborhood in northwest St. Petersburg. He uses a dipper to collect a water sample, which he then will analyze. The stage reached by any mosquito larvae in the sample tells him whether the infestation is treatable.

SEMINOLE -- Hatcheries, hatcheries, hatcheries.

Mosquito hatcheries are everywhere.

"Look over there. A birdbath," groans Hank Marquardt, who has trained himself to think like a mosquito. "Guarantee you larvae is boiling in that bird bath. See that house? Holy moly! Guarantee you'll get chewed up in that yard. Flower pots. Bet they're filled with water. Mosquitoes lay eggs in flower pots."

Driving through Pinellas County, he is on his daily bug hunt. Other motorists are watching traffic, chatting on cell phones, looking for a place to buy bagels. He is thinking like a mosquito. What does a mosquito need most? Blood, of course. Females require blood to manufacture eggs. What else? A mosquito needs a place to lay eggs.

That stinky bait bucket collecting rain next to the tool shed? It might hold hundreds of mosquito larvae. In a day or so, they'll hatch and go looking for a perfumed neck.

Marquardt, who works for Pinellas County Mosquito Control, has matched wits with the enemy for a quarter of a century. His weapons include chemicals and common sense. When he finds a puddle of mosquito eggs, he treats it with a compound that prevents the mosquitoes from hatching. As a last resort, he'll spray pesticides on adult mosquitoes from the back of his truck.

But the most effective treatment, he has found, is public education. He tells residents the truth about their backyards.

"Ma'am, do you have any water, like a puddle, in your yard?"

She says no.

He drives over.

No puddle. But a birdbath. And a bucket where she is trying to root a frangipani. Both have been breeding the mosquitoes that have been biting her. He drains her mosquito hatcheries.

Some summers he emerges victorious. But the summer of 2001 may belong to the mosquitoes. Everything is perfect for them. After two dry years, rain is falling in earnest. Water is puddling in everything from ditches to discarded bottle caps. Yes, even a bottle cap is a potential mosquito hatchery.

Mosquitoes will lay eggs in any place that's wet enough. Mosquito swat-team members like to tell the famous story about the larvae swarm once found inside a nursing home -- in a water glass containing false teeth.

Mosquitoes once made Florida almost uninhabitable. American Indians and early pioneers lit fires and stepped into the smoke in the height of summer rather than face the swarms. They died from mosquito-transmitted malaria and yellow fever anyway.

Hank Marquardt prepares to zap some mosquitoes with pesticide, an attack that does not work on every species.

Then came sweet civilization. Window screens thwarted mosquitoes. Draining swamps eliminated mosquito habitat. But not enough for some. As Florida grew, new residents demanded professional mosquito control. The insecticide DDT, sprayed from airplanes, helped. The poison also sickened other wildlife and even people. The mosquitoes? They eventually grew immune to DDT.

Other poisons came along. Some worked, some didn't.

Stalemate.

Now the scales of battle might be tipping again. Blame it on global warming, blame it on something else, but mosquito-borne diseases are migrating back into the United States. Already this summer a boy in North Florida has died from mosquito-transmitted encephalitis, a brain fever. A similar mosquito disease, West Nile virus, killed nine New Yorkers last summer. Now it has shown up in Florida.

Floridians probably face greater dangers from interstate traffic and slippery bathtubs. That said, it is likely to continue to be an itchy summer. Mosquito repellent and Benadryl are selling like ice cubes in the desert. Pinellas Mosquito Control has fielded more than 15,000 complaints from itching residents since July.

"I can't go outside," whines one resident.

"They're eating me alive," cries another. "You've got to kill them."

"We're doing our best," Marquardt tells them.

Marquardt, 52 and unfailingly polite, would like to tell them, relax, we're going to kill them all. But it's not going to happen. Mosquitoes have been on earth millions of years longer than Homo sapiens. They know how to endure.

Modern Floridians are spoiled. Some of us want the oceans rid of sharks. Some demand that alligators be eliminated from their lakes. We complain about drought one moment and rain the next. Someone builds a $350,000 house in a golf-course blessed subdivision -- a subdivision constructed on the edge of a mosquito-infested swamp. As a taxpayer, the new resident wonders why the county can't kill all the mosquitoes.

"People want us to fog every night," Marquardt says. Fogging, the heavy artillery, is the last resort of mosquito control. The fog is a strong chemical, Anvil 2+

2 ULV. It can be a hazard to humans and to domestic animals. So it's typically used in the wee hours before dawn.

From flower pots sitting in yards, from bird baths, even from the throats of bromeliad plants, Hank Marquardt gathers water, testing to see if any mosquito larvae present are vulnerable to a pesticide that will keep them from maturing.

Mosquitoes dumb enough to fly into the fog drop dead immediately. The fogging trucks, roaring up and down suburban streets, may make some homebound folks feel better about their tax dollars. But mosquitoes hiding in the back yard, or swarming a few blocks away, likely will survive.

The more effective treatment is less dramatic -- and less appealing to Floridians who are looking for something akin to a mosquito atomic bomb. It's Marquardt and the other dozen bug hunters driving around Pinellas looking for places where the county's 28 species of mosquitoes might breed. (Every county in Florida, by the way, has its own mosquito swat team.)

"I tell people, don't think big picture." Marquardt says. "People see a lake and they think that's where the mosquitoes have to be breeding. Probably some are. But it's better to think small picture. They are probably hatching in rain gutters clogged with leaves all across the county."

He drives into an upscale neighborhood near Boca Ciega Bay. Huge oak trees shade two-story luxury homes. Ferns provide lovely hiding places for mosquitoes. Meanwhile, Marquardt zeroes in on the yards graced by bromeliads. Their wide leaves funnel water into the heart of the plant. With a turkey baster -- not all mosquito-control equipment is high tech or even expensive -- Marquardt sucks the water out of the hearts of the bromeliads.

Bromeliad plants are notorious mosquito hatcheries for a variety called Wyeomyia vanduzeei. It's a biter, even during daylight. It enjoys shade and juicy gardeners. Apparently it lays eggs only in bromeliad plants.

"Mosquitoes, depending on the species, have special needs."

Some mosquitoes lay eggs only in crab holes. Some in tree caverns. The Aedes aegypti favors water-filled containers often stored carelessly around homes. Aegypti mosquitoes sometimes transmit disease.

The most aggressive biters in Florida, fortunately, have never been known to be more than a nuisance. But what a nuisance. Salt marsh mosquitoes, as several species are known, emerge by the millions from coastal mangroves during warm, wet weather. They never sleep. They are capable of flying 20 miles in a day. Run, and they'll chase you.

They will fly into your nostrils, into your eyes, and into your mouth when you scream. In Pinellas County, Marquardt sometimes will pause at the edge of the mangroves and offer his arm in the name of public service.

Salt marsh mosquitoes, 10, 20 or three dozen, will light on him. Within a minute.

That means serious mosquitoes.

Each Florida County has a corps of skeeter fighters that monitors standing water in communities and tries to wipe out mosquitoes before the insects become biting adults. Look at the small picture, Hank Marquardt advises. Get rid of standing water in your yard, and you may not need to contend with the fogging machine.

"I want to check out a swamp," he says, parking near the mangroves at Boca Ciega Millennium Park. Nearby residents have been wearing out their phones calling mosquito control.

Marquardt hauls on his boots, wades into the water. Salt marsh mosquitoes whine around his ears and land on his blue shirt. He carries a dipper, a cup at the end of a long pole. He scoops water. Sure enough, the dipper is filled with a slimy punch containing dozens of swimming little black dots. Larvae. Either Aedes taeniorhynchus or A. sollicitans. He treats the swamp with microscopic granules. Larvae eat the granules and fail to mature.

"One more stop now," he says.

He visits a nearby neighborhood, ambles behind a huge new house built where years ago nobody in his right mind would have dared live. American Indians stayed away during the summer, but modern Floridians will live in a mangrove swamp and wonder why they can't hold a barbecue in an August twilight.

It hasn't rained in a couple of days, so everything has pretty much dried up except for a little puddle behind the house. Marquardt checks out the puddle, which is 4 feet wide and 10 feet long, and extends his arms to the heavens. Suspicions confirmed.

"I'd say there's about 10,000 larvae in this one puddle," he says. "I'm going to kill the mosquitoes in this puddle, but there are lots of puddles and what-not that we're not going to find.

"Like I tell people, we can't get them all."

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