Minnesota's summer forecast calls for an abundance of mosquitoes

With temperatures in the 70s, sunny skies and no bugs, Thursday was an ideal day for winter-weary Minnesotans itching to get outside.

"This is the golden time of year," said Alex Carlson with the Metropolitan Mosquito Control District (MCCD). "Enjoy it while it lasts."

The honeymoon will soon be over. Weekend rain is expected to trigger the first hatch of mosquitoes, which will have us swatting and slapping by the middle of next week — and all summer long, as this year's swarm looks likely to be the largest in years.

"We have been spoiled from the mosquito standpoint," Carlson said, noting that the relatively dry summers for the past two years have kept the mosquito population significantly below the 10-year average.

Black flies may also be more prevalent this spring, but there might be slightly fewer ticks, he said.

Near-record snowfall — the 90.3 inches that fell at Minneapolis-St. Paul International Airport made this winter the third-snowiest in 142 years of recordkeeping — followed by the high water left when it melted created the perfect environment for a bumper crop of mosquitoes, Carlson said.

Swamps, basins and ponds that had gone dry filled up this spring, creating more breeding sites. Assuming the Twin Cities gets average rainfall over the next 90 days, as the Climate Prediction Center forecasts, "we will have more mosquitoes than we have in the past two years," Carlson said.

The surge in floodwater mosquitoes — the most common of the 52 varieties found in Minnesota — will be noticeable across the Twin Cities area, Carlson said. But the biggest concentrations will be found in Anoka County, which has more insect-producing habitat than anywhere else in the metro. Stagnant pools of water, where larvae hatch, are also prevalent in northern Hennepin and Ramsey counties, he said.

This week, the MCCD began its annual treatment of 200,000 acres of wetlands in the metro to suppress an anticipated mosquito population that could double last year's numbers. Helicopters flew over wetlands, dropping pellets containing a bacterium called Bacillus thuringiensis israelensis, or Bti, into the water. MCCD crews also waded through swampy areas to spread the pellets, which have a texture resembling Grape-Nuts cereal. Larvae ingest the pellets, killing them on the spot, the MCCD said.

The pellets are not harmful to humans or other animals, Carlson said.

But humans need to do their part, he added. Female mosquitoes need blood to produce eggs and are drawn to those who use perfume or hairspray or wear brightly colored clothing. Women who are pregnant, people with high body temperatures and those who drink alcohol or sweat while exercising also tend to be targets, Carlson said.

To fend off the pests, bug spray works, he said — repellent with permethrin is particularly effective, though it should be applied only to clothing and gear and not directly to the skin. Repellents containing DEET, picaridin and oil of lemon eucalyptus are among the repellents the EPA and CDC recommend as safe to use on skin.

People can also help decrease the number of mosquitoes by emptying birdbaths, spare tires, trash cans and other places where water collects.