Mosquito Control Inspectors Donate Bodies to Science

KEY BISCAYNE, Fla., July 30, 2009— -- Mick Espaniel stood stoically as two bloodsuckers attached themselves to his cheek. Another pair were clamped to his pants leg. And others were eyeing the juicy section on the inside of his elbow.

I had doused myself in DEET, and still scratched my own elbow and slapped at my neck. And yet Espaniel, a 38-year-old mosquito control inspector for Miami-Dade County, stood stock still, then casually swept a couple of pests off.

Espaniel, a thoughtful pest expert who said he is just as easily bitten as anyone else, was conducting what they call -- in the business -- a Landing Rate test.

We had driven out to a mosquito infested mangrove swamp near on Key Biscayne. Leaving the car, we walked over a small knoll and onto a dirt path leading into a knot of mangroves. The dirt was pocked with crab holes, the air was crowded with cobwebs and hovering mosquitoes.

A Landing Rate Test, requires a Mosquito control inspector to stand on mosquitoes' home turf and donate his body to science. Without protection, without even a long sleeve shirt, Espaniel is tasked with counting how many mosquitoes land on his body in a minute. We stayed out for about 10 minutes. Within a minute he has a pretty good idea.

"They're attracted to the carbon dioxide we exhale, so they flock to you pretty quickly," he said, as I immediately tried to hold my breath. They are also attracted to dark colors -- there was little I could do about my jeans.

It was a losing battle.

Having harassed man and beast for the past 100 million years or so, mosquitoes perfected their technique over time. According to Sandra Fisher, the director of Miami's mosquito control division when they bite, mosquitoes first inject their victims with an anesthetic -- so you don't realize they've just sunk a stinger into you. They then release a coagulant to prevent your blood from clotting and spoiling their feast. And that coagulant, and the immune system's response to it, causes the skin irritation.

Every day, inspectors around the country like Espaniel here and around the country use their bodies to determine the severity of mosquito infestations.

It may seem primitive, Fisher said, but "landing tests remain one of the best methods of determining mosquito density in a given area."

Mosquito control inspectors' tactics vary across the country, but generally include anything that will increase the chances of getting attacked: standing still; using no repellents; disturbing surrounding vegetation (letting them know you're there); conducting the test at dusk or dawn; and often going out with some exposed skin.

"I'd give this a landing count of six or eight, which is not bad," he said during our dawn landing rate test. That's because the county had sprayed the area a week previously.