With all this rain, mosquitos are back in Twin Cities with a vengeance

Fueled by Minnesota’s soggy start to spring, mosquitos are appearing in high numbers not normally seen at this time of year.

And they are generating quite a bit of buzz and bites, particularly in the southwest, east and north metro.

Last Tuesday, the Metropolitan Mosquito Control District (MMCD) set a daily record when 315 people called, emailed or filled out an online form to make reports and comments about the tiny insects and, of course, complain.

Typically, the agency tasked with keeping the mosquito population down might hear from 100 people on a busy day, said MMCD spokesman Alex Carlson.

“People are noticing,” he said. “We are getting a lot of calls from hotspots.”

The heaviest concentrations of mosquitos have been in cities along and near the Minnesota River, such as Jordan, Chaska and Belle Plaine. Flood warnings are in place for the next few days along the Minnesota and the South Fork of the Crow River in that area, the National Weather Service said.

“Scott and Carver counties have been inundated,” Carlson said.

The pests also are out in full force in northern Anoka County communities of Linwood Township, Ham Lake and East Bethel. But they are perhaps thickest in the east metro.

MMCD workers use nets to collect water samples from wetlands, ponds and marshes in the metro area. When samples yield two to three larvae per dip, that area is identified as a place meriting treatment. In North St. Paul in Ramsey County and Baytown Township in Washington County, recent samples have produced 50 larvae per dip, Carlson said.

“That is way above normal,” Carlson said.

Though not quite at record levels, the large hatch has this year’s crop trending well above the 10-year average and about on par with 2023, which was one of the largest in years.

A dry winter that included the second-longest streak without measurable precipitation (Feb. 16-March 20) had MMCD officials hopeful that 2024 would be a better year for people heading outdoors.

But by the end of March, a combination of heavy rain and snow erased precipitation deficits for the month. Ever since, a steady diet of weather systems have brought precipitation to the metro on average every three to five days. The Twin Cities received 12.41 inches of precipitation from March through May, or 41% more than normal.

Another soaking this week pushed the Twin Cities over the 13-inch mark for the year, making 2024 the wettest spring since 2019 and the 12th-wettest start to the year since weather records began in the 1870s, said Pete Boulay with the Minnesota State Climatology Office.

“We’re just not used to being this wet,” Boulay said.

All that has allowed the mosquito population to grow rapidly. Along with leaving standing water — prime habitat for larvae — the frequent storms have hampered MMCD’s effort to apply treatment. The agency has not been able to send its helicopters skyward often, and high water on the rivers have kept boats docked, making it hard to reach known mosquito-producing habitats, Carlson said.

“It’s put a damper on things,” he said, “We know we are missing spots, but we can’t get out there. Treatments have been slowed.”

Helicopters were flying Wednesday.

Carlson said the MMCD has also noticed a bigger population of black flies this year when compared to previous years.

A prolonged dry spell could help bring down the population of mosquitoes and black flies, Carlson said. The forecast calls for mostly clear skies through Tuesday with little precipitation, the National Weather Service said.

In the meantime, the best advice to avoid mosquito bites is to apply insect repellant and “wear long, light and loose-fitting clothing,” Carlson said.