Weekly Update – May 16th – Not Many Adult Mosquitoes Yet, Ticks are Prevalent
May 24, 2022
Weekly Update – May 31st – Adult Mosquito Numbers Accelerating in Some Areas
June 7, 2022
Adult mosquitoes and black flies are starting to emerge in some areas with the Southwest metro being the first hot spot.
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.
Rain leads to mosquitoes and since the Twin Cities has had several rain events over the past two weeks, some contributing an inch of precipitation or more, more mosquitoes are emerging. Most CO2 traps still collected fewer than 10 adult mosquitoes each last week, but a few in Carver County, Anoka County, and Dakota County had more than 50.
According to MMCD assistant entomologist Scott Larson, "Most of the mosquitoes in the CO2 traps were Aedes vexans, and only in NE Anoka and N Washington counties were there significant numbers of spring Aedes." Aedes vexans are a summer floodwater mosquito, meaning their eggs hatch after rain events, and they are the most common nuisance mosquito species in Minnesota. After the recent rain, the Twin Cities is likely to see more mosquitoes emerging District-wide within the next few weeks. May saw around the expected amount of precipitation statewide, according to the DNR and the National Weather Service is no longer predicting a drier than average summer for the Twin Cities.
As expected, black fly/biting gnat numbers are beginning to increase in parts of the District. Last week southern Dakota County, southern Hennepin County, and several spots in Carver County had traps that collected over 100 black flies. If you are noticing high numbers of adult black flies, please use our Submit a Tip form and let us know!
Here are the mosquito trap counts from last Monday, May 23rd:
MMCD field staff completed treatments for cattail mosquitoes last week.
Cattail mosquitoes (Coquillettidia perturbans) are a unique species that over-winters as larvae by attaching to the roots of pond vegetation (often cattails) and emerges once per year, around the beginning of July. Last fall our field staff visited sites that historically have held cattail mosquito larvae to find where they were present and last week we completed air treatments for this species. Altogether field staff treated 18,514 acres of cattail mosquito treatment via air.
Rain over the weekend likely did not accumulate enough to trigger another major mosquito hatch, but District staff will be out throughout each county this week checking for larvae. Please help us out by reducing mosquito habitat on your property - check your yard after any rain to see if there is any standing water and eliminate it promptly.
Ticks continue to be quite active throughout the District, so be sure to check yourself, your children, and your pets any time that you are in a wooded area, near long grasses, or anywhere outdoors that could harbor ticks. For more information on tickborne disease visit the Minnesota Department of Health website.
MMCD will be at upcoming events in your area!
One of the best parts about summer is that MMCD gets to spend time in the community providing educational opportunities for residents to learn about mosquitoes, ticks, and black flies. This coming weekend we will be in several spots throughout the metro. On Saturday, June 4th we will have a booth at Lake Phalen Water Fest in St. Paul. Also on Saturday, we will have a float at the Tator Daze Parade in Brooklyn Park where you also might meet our mascot Vectoria.
There will be several more opportunities to connect with MMCD in-person at public events. View our events calendar for the complete list!
For the latest updates on mosquito control, disease activity, and planned treatments, follow MMCD on Twitter or Facebook.
