They're back. And they're hungry.
The wetlands of west Davis County are the breeding grounds for hordes of mosquitoes that hatch in the protected areas, then buzz into nearby neighborhoods to snack on residents, Mosquito Abatement District Manager Gary Hatch said Tuesday.Hatch told the Centerville City Council the district is getting calls and has started its summer program of spraying, but the task is daunting. He predicted it will be a tough summer, with plentiful mosquitoes.
Hatch is the district's first full-time manager, hired in January 1993. He's been battling mosquitoes for 17 years, since he was 16 and a part-time summer worker in the Box Elder County abatement district, Hatch said.
Council members were gladdened to learn that Hatch has moved to Centerville, into what district board member Stan Green noted is "one of the most heavily infested areas of the city."
"Is that near my house?" asked Mayor Priscilla Todd, hoping for some extra spray sorties by the district's truck-mounted fogger.
Hatch said control efforts are complicated and the days of laying in a stock of DDT at the beginning of summer and spraying everything in sight are long gone.
Federal regulations governing pesticide use are complicated and boost the price; wetland preservation regulations and restrictions on control measures the district can use in the Farmington Bay Wildlife Refuge also hamper their efforts, Hatch said.
And, with a flying range of 10 to 15 miles, a mosquito's range is such that there's little an individual homeowner can do to control the pests, he said.
Citronella candles may keep them away during a backyard barbecue, Hatch said, "if you can stand the smell."
As for the electronic bug zap-pers that are popular, "they do kill a few. But they also attract them. The joke is the thing to do with a bug zapper is to buy one and give it to your neighbor to use," Hatch said.
The piles of dead bugs that build up under the zappers will contain only about 10 percent mosquitoes, Hatch said, the remainder being moths and nonbiting midges, flying insects that resemble mosquitoes.
"Midges don't bite. Only mosquitoes bite. And only the female mosquitoes bite," Hatch said, drawing a few chuckles from the male members of the City Council.
"Thank you for that, Gary," responded Councilwoman Francine Giani.
Hatch said mosquitoes are attracted to people by the carbon dioxide in their breath.
One effective control method the district uses is a small fish, the gambusia. Aggressive feeders on mosquito larvae, the fish do well in decorative ponds and yard fountains, Hatch said.
Because they are aggressive feeders, the young fish, called fry, tend to dominate the fry of other fish, so federal endangered species regulations bar their introduction into streams, ponds or freshwater areas of the Great Salt Lake marshes, Hatch said.
Hatch noted there are 40 species of mosquitoes native to Utah, of which 15 are found along the Wasatch Front. Most have a lifespan of seven to 10 days, he said, but millions of eggs are in the marshes, waiting to hatch.
The mosquito population declined somewhat during the drought years of the late 1980s, Hatch said, but recent wet years and the re-emergence of the marshes around the lake, especially the Farmington Bay refuge, have reversed that trend.
Population growth has also pushed subdivisions into what used to be mosquito-infested pastures adjacent to wetlands, he said.
The abatement district maintains a flock of chickens at its west Kaysville office, running blood tests on the birds to check for mosquito-borne encephalitis, Hatch said.
There hasn't been a case of human encephalitis along the Wasatch Front since 1958, according to Hatch, but two fatal cases were diagnosed in horses last year, one in Moab and one in the Uintah Basin.
Another mosquito-borne disease, canine heartworm, has appeared in Utah within the past four years, Hatch said. He urged that dogs be put on heartworm preventive medication during the mosquito season.