West Nile battle moves to streets of Vermillion A cloud of insecticide is emitted by equipment in the back of a city pickup driven by Todd Schultz, Vermillion's mosquito control specialist. The mist kills adult mosquitoes, and will hopefully help prevent citizens from acquiring the West Nile Virus, which is spread by the biting insects. by David Lias Todd Schultz reached into the cab of a city pickup Wednesday afternoon, and snapped on a pair of latex gloves.
He then hopped into the back of the pickup, and pried the cap off a large metal can.
The liquid inside the container is relatively harmless to people and the environment.
It is, however, deadly to mosquitoes.
He carefully poured the liquid insecticide into a machine dubbed London Fog.
At first glance, the contraption resembles some sort of high tech furnace, with a small, curved chimney.
Instead of smoke, however, a fine mist of the insecticide was emitted from the "chimney" as Schultz slowly drove through Vermillion neighborhoods.
At 8 p.m. Wednesday, he took the city's fight to control the West Nile Virus to the streets.
He slowly drove through both commercial and residential areas in the northern half of the Vermillion, followed by a fine, mosquito-killing chemical cloud.
"We're using Scourge insecticide," Schultz said Wednesday afternoon from the back of his pickup. "It's a synthetic toxin that's based on a natural toxin that flowers use to keep pests off."
With the introduction of the mosquito misting, Vermillion is now using a three-pronged approach to control the insects' population.
"The best way to control mosquitoes is through habitat elimination," Schultz said. "But it's been a wet year, and there are places, like fields and ditches, that are going to remain filled with water."
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Next to habitat elimination, the use of larvacide is most effective. The city has been treating areas of standing water with the environmentally-friendly chemicals that kill mosquito larvae since this spring.
But careful monitoring of the insects' population in Vermillion compelled city officials to add that third prong � misting � to hopefully keep West Nile at a minimum.
"We have six mosquito traps set up throughout the city," Schultz said. "By comparison, Sioux Falls has 10, so we have a good monitoring program going."
Misting, he said, "is a last resort" in mosquito control. The use of larvacide in standing water is cheaper and more effective, killing from 60 to 70 percent of mosquito larvae.
Vermillion's mosquito traps have indicated a growth in the insects' population here. That has caused concern among city leaders, for Clay County was hit hard by the West Nile Virus last year.
There were over 1,000 cases of West Nile reported in South Dakota in 2003, and a dozen deaths.
The first casualty was a Clay County man from rural Wakonda.
The use of the mosquito mist isn't as effective as larvacide. It should, however, help knock down adult mosquito numbers in the city, Schultz said.
"With the use of the larvacide, 40 percent of the larvacide become adults," he said. "Misting is 50 percent effective, so if you can kill 50 percent of the adults, you're eliminating the mosquito population by a lot."
Winds were gusting Wednesday afternoon as Schultz poured the insecticide in the tank of his London Fogger. Weathermen predicted calm weather by 8 p.m. in the area.
Their forecasts were accurate.
"The wind has to be 10 mile per hour or less for us to mist," Schultz said. "And, we drive the pickup at 10 miles per hour. We're putting out six ounces (of insecticide) a minute. You can do more if you have a heavier amount of mosquitoes, but we feel this is the best rate to be both effective and economical."
Weather conditions had grown so quiet by 8 p.m. Wednesday that the cloud of insecticide floating above Schultz's pickup didn't quickly disperse as he drove on Vermillion streets.
"It drifts usually about 300 feet," he said. "This method is much neater than the fog machines that were used years ago that made quite the mess."
If the weather cooperated, Schultz was scheduled to begin misting the southern half of Vermillion Thursday evening