Metro area group plans fight against mosquitoes as temperatures rise, spring floods continue

Minnesota prepares for mosquito season

Minnesota prepares for mosquito season

With the warmer weather, and lots of standing water, Minnesota is on the cusp of a mosquito comeback.

“We didn’t have a battle with mosquito last year, but the battle resumes summer 2023,” says Alex Carlson, a spokesperson with the Metropolitan Mosquito Control District, or MMCD for short.

“I definitely am thinking it’s going to be higher, there’s going to be more mosquitoes this year for sure, especially compared to last year,” adds Kathy Beadle, the group’s field operations supervisor.

For the last two years, the state has experienced drought. But this year is different, experts say.

University of Minnesota Entomologist Jon Oliver says our record snows and snowmelt have created the ideal breeding ground for mosquito eggs, with all that water.

RELATED: 2023 mosquito season expected to be ‘significantly delayed’ due to cold air, water temperatures

“So, the most abundant mosquitoes in Minnesota are floodwater mosquitoes,” Oliver explains. “Most of the mosquitoes, especially those floodwater mosquitoes, actually lay eggs at the end of the summer, and then the eggs lay over the winter and they hatch when temperatures are warm enough and they get wet in the spring.”

It’s why a field team from the MMCD collects larvae samples and sends them to a lab, trying to pinpoint the locations of harmful mosquito strains.  

RELATED: First metro mosquito larvae of 2023 season found

Carlson says there are 53 mosquito species living in Minnesota, and that 20 of them bite humans.

“Each time we get a heavy rainfall, more eggs are going to hatch, and when these eggs hatch, they’re in the water for about a week,” he says. “And then they come out as an adult mosquito, and that’s what you have to watch out for.”

The team’s silver bullet is a soil bacteria called Bacillus thuringiensis, subspecies israelensis, and more commonly known as BTI.  

Discovered in Israel- hence its name- the bacteria, infused into a corn cob granule, shreds a larva’s digestive system.

“The mosquito larvae, they’ll eat it,” Beadle notes. “And so, they’ll eat the bacteria, and it goes into their stomach, and it just crystallizes, and it doesn’t allow them to eat anymore, and that’s how it kills them.”

She adds the bacteria is not harmful to humans or other animals, but specifically targets mosquitoes.

The team uses a helicopter to treat affected lakes and ponds with applications of BTI.

MMCD expects to cover 200,000 acres of waterways this summer, but much of this will depend on how much rain the state receives in the coming months.

However, the process is not a one-off. The team will have to reapply the BTI after any significant rains of an inch or more, and they’ll repeat the process throughout the summer.

Strong winds delayed the application on Monday and Tuesday, but the team expects to try again on Wednesday with the hope of better weather.

“We’re for sure going to be seeing more mosquitoes than we did in the past two years,” Carlson says. “Whether it’s significantly worse, it’s hard to say yet. That will depend on what rain happens in the next couple of months.”