Weekly Update – June 17th – A Few Mosquito Hot Spots, but Overall Below Average
June 25, 2025
Weekly Update – July 1st – Are We at Peak Mosquitoes for 2025?
July 8, 2025
We are the closest to average we have been since collections began in mid-May.
Mosquito numbers increasing in part due to cattail mosquitoes emerging.
Every Monday night starting in mid-May through September, the Metropolitan Mosquito Control District sets out a variety of mosquito and black fly traps throughout the district and employs a network of sweep net collections done by employees and volunteers. Any insects collected are brought back to our lab on Tuesday to be identified throughout the week with maps published to show current mosquito and black fly activity.
Our models have long been forecasting a mosquito surge around the beginning of July and we are starting to see the beginnings of that increase from last week's surveillance. On June 24th, the highest number of cattail mosquitoes were collected in CO2 traps since 2021 and that number will likely climb as we head into the early weeks of July. The collections do demonstrate some success of MMCD's larval control efforts as the highest collections came from lower populated areas that received less treatment than areas with a high population density.
According to MMCD Entomologist, Dr. Scott Larson, "We averaged almost 250 human-biting mosquitoes per CO2 trap last week and the 10-year average is ~300 for that week of the year. This week leading into the Fourth of July is that time of year when we see the peak abundance of mosquitoes in the District. In case anyone wonders why, the peak coincides with the mass emergence of cattail mosquitoes in addition to all the floodwater mosquitoes out there. I do expect the number of mosquitoes this week to continue to increase although I'll be surprised if we pass the 10-year average at all this season because of our slow start."
Below are maps showing all human-biting mosquitoes (left) and cattail mosquitoes (right) collected in CO2 traps on June 23rd-24th:
Helicopters and Ground Treatments Galore Leading up to the 4th of July
Over the past several days most counties within the District received over an inch of rain, sometimes spread out over several days. This has led to mosquito larvae developing in ponds, wetlands, and other habitats all over the place. Helicopters were busy over the weekend and continue to be active as we get closer to the 4th of July. As of June 30th, we have treated over 22,000 acres by helicopter with over 7,000 still to go, making this one of the largest mosquito broods of the year so far.
Staff have also been active doing ground treatments throughout the Twin Cities. Small to medium-sized wetlands are treated by hand or by a drone, so staff have been active in parks and neighborhoods all week to reduce mosquito numbers heading into the 4th of July. As a reminder, you can see the latest planned treatments on our website and sign up to receive e-mail alerts for your county.
Speaking of drones, QCTV recently did a story about MMCD's larval control program and how we are using drones this year to help. Check it out below:
