Weekly Update – April 27th – First Round of Larval Treatments Complete
April 27, 2026
Black fly larvae on underwater vegetation.
Helicopter treatments took place last week and will finish up this week.
The colder start to May has allowed MMCD staff to get a good start on a lot of preventative work that will keep mosquitoes from becoming abundant in the months ahead. Colder temperatures slow down larval development and keep them in the water for longer, giving MMCD staff more time to get to all of the surrounding areas.
We have received a few reports of mosquito sightings, but we don't start our official adult mosquito surveillance until next Monday, May 11th (pending temperatures allow). Until then most of our data comes from collections of larval mosquitoes that help determine our treatments. Last week the Twin Cities received more than an inch of rain so helicopters were out several days, as conditions allowed, treating a total of 10,080 acres. Mosquito control helicopters will be back out today completing treatments in areas where larvae hatched last week with 10,453 acres planned as of now.
Last week, staff at the Metropolitan Mosquito Control District checked 1,952 large wetlands and 707 contained mosquito larvae above threshold (about 36%). Most of the species were in the spring Aedes family, which are sometimes called "snowmelt mosquitoes" because they are the first to hatch when the snow melts in early spring.
It's looking cool and dry this week, meaning there likely won't be a lot of mosquito eggs hatching and those that have emerged as larvae (and don't get treated by MMCD) will stay in the water for a while. Even the adult mosquitoes that may have emerged will be quiet this week as mosquitoes cannot fly when temperatures are below 50 degrees and several evenings this week are expected to be below that.
Black fly (biting gnat) activity is picking up.
This week we received several reports from residents that black fly activity was starting to pick up. These small flies, also known as biting gnats, emerge from moving water in rivers and streams. They can be aggressive biters and often swarm the head and neck. There are steps you can take to reduce getting bitten by black flies and you can learn more at our Black Fly program page.
Last week MMCD staff inspected 30 small streams and large rivers for black fly larvae and completed 37 black fly treatments.
Here is an infographic we created several years ago for tips on reducing black fly bites:
May is Lyme Disease Awareness Month - Look Out for Ticks!
May is one of the most active times for blacklegged ticks (deer ticks) because it's the beginning of the peak for nymphal deer ticks and a high time for adult deer tick activity. Please remember to check yourself for ticks any time you are outside and take preventative steps to reduce getting bitten.
Here is our post from a previous Lyme Disease Awareness month. Look for our update next week on some new tools we have to help combat mosquitoes and ticks.
Events This Week:
- Monday, May 11th - Come see MMCD at the Credit River Town Park Meeting in Prior Lake!
Know any teachers? May is a great month for a school presentation from mosquito control! Staff at MMCD offer dynamic presentations and can bring microscopes, live specimens, and other cool hands-on science. We can even take the class outside and demonstrate how to dip for larvae! Contact Alex Carlson if you are interested in learning more.
MMCD in the News:
- CBS Minnesota (WCCO) talked to health professionals, including MMCD Vector Ecologist Dr. Jordan Mandli, about the outlook on the 2026 tick season.
Introducing the 2026 MMCD T-Shirt!
Duunnn dunnn… duuuunnnn duun… duuunnnnnnnn dun dun dun dun dun dun dun dun dun dun dunnnnnnnnnnn dunnnn...
We're gonna need a bigger dipper...
We are excited to unveil our new t-shirt for 2026! You may see MMCD staff sporting these sweet Jaws themed shirts at public events in 2026. This design was created by Rosa M. from MMCD's Andover facility.
Want your chance to rock one of these? Sign up for "The Weekly Buzz" newsletter with Weekly Mosquito updates. Each week there will be a trivia question at the end. Two correct answers each week will get a shirt!
Enter your e-mail address below to sign up now!
