Drones Are an Important Part of MMCD’s Mosquito Control and Surveillance. Learn Why!
June 27, 2024
Weekly Update – July 2nd – Mosquito Numbers Increase, but Stay Below Average
July 9, 2024
Mosquito numbers began to inch back up overall, but a surge likely won't be coming due to the lack of cattail mosquitoes.
Mosquitoes inched back up, but remained below average across the District last week. Cattail mosquitoes have yet to show up in a significant way.
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 month of June ended with mosquitoes increasing slightly, but not quite back to the peak that we reached during the week of June 11th. Consistent rain throughout the month of June led to an abundance of mosquitoes in some areas, but the three preceding years of drought likely kept the numbers from increasing significantly. Based on the 10-year average, the peak of the season for mosquitoes should be around the first week of July, but we likely won't see that this year due to the absence of cattail mosquitoes:
Cattail mosquitoes (Coquilletiddia perturbans) are a unique species that hatch in the fall, overwinter as larvae, and emerge once per summer in a single brood. Because they hatch the preceding year, our entomologists look to last year's surveillance and precipitation to predict the species numbers in the coming year and they had predicted a low year in 2024.
Disease vectors are on the rise and West Nile virus risk will remain a concern throughout the rest of the summer. MMCD assistant entomologist Dr. Scott Larson says "Culex are abundant (mostly Cx. restuans), but Cx. tarsalis, our main West Nile virus vector, is also abundant in some locations."
After a low week, black flies have made a pretty significant comeback especially along the Minnesota and Mississippi Rivers. This is likely associated with the record flooding that has been occurring after weeks of heavy rain. MMCD has not been able to conduct our usual black fly surveillance and treatments due to dangerously high water levels.
Here are the mosquito trap counts from last Monday-Tuesday, June 24th-25th:
Reminder: Remove standing water and reduce mosquito habitat!
One of they symptoms of the excessive rain we've had over the past several weeks is standing water pooling in places where it probably shouldn't be. Unexpected water sources can become mosquito habitat if left to stagnate and it's important to remember to check your yard and neighborhood for opportunities to "dump it out."
Recently, we found mosquito larvae in a tree watering bag:
Check out the MMCD Resident's Guide for tips to deal with standing water at your property.
Learn more about the MMCD Monday night surveillance network.
All of the data we provide in these weekly posts are thanks to our Monday night surveillance network. Each Monday night, dedicated staff members set up a variety of traps and some offer themselves as human bait to trap and collect mosquitoes.
Recently, the Star Tribune published a story about the Monday night network:
