Weekly Update – June 25th – Mosquito Numbers Stay Below Average, Black Flies are Back
July 2, 2024
Weekly Update – July 16th – Have We Passed the Mosquito Peak for 2024?
July 25, 2024
During the week that is the typical peak of mosquito season, we are significantly below the average.
Mosquito numbers increased again this week, but remain below the 10-year average and behind the spring peak.
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.
The first week of July is typically when mosquito season in the Twin Cities peaks, according to the 10-year average of adult surveillance. However, despite a very rainy spring and a surge in the early months, we are well below the 10-year average in July of 2024 and haven't quite reached back to the spring peak of over 300 mosquitoes per trap that were collected the week of June 11th.
Despite frequent rainfall this year, mosquitoes have not quite rebounded to levels we've seen in the past. MMCD Assistant Entomologist, Dr. Scott Larson explains why: "I think the reason we aren’t seeing huge numbers of mosquitoes (despite the near constant rain) is because we are largely missing our normally abundant Aedes vexans and Coquilletidia perturbans mosquitoes. Both species are highly dependent on rainfall and the last 3 years of drought have really crashed their populations." Larson projects that next year will see higher numbers of these two species as this year has worked as a rebounding year.
Black fly numbers are surging especially along the Minnesota River, likely due to record flooding. The trap near Belle Plaine captured over 14,000 last week in one night! High water has made it unsafe to do our typical black fly treatments, which means the numbers are much higher than they'd normally be.
Below are the maps from Monday-Tuesday, July 1st-2nd:
Which mosquito repellents work the best?
It finally feels like summer temperatures and we may even be getting a break from the rain over the coming two weeks. As you prepare to venture into the outdoors, be sure to stock up on your favorite bug spray and make sure it's a type that actually works. We recommend EPA registered insect repellents in our Resident's Guide, which may be a good starting point.
Recently, KARE 11 did an investigation with the help of MMCD and Consumer Reports to determine which bug spray actually works the best (and which ones don't work at all). Check it out below:
