VIDEO: Mosquito Bite Games – Habitat Edition
September 26, 2025
Metropolitan Mosquito Control District 2025 Season Highlights
November 24, 2025
Mosquitoes have mostly wrapped up their activity for the season as we head into October.
The last week of mosquito surveillance ends at the beginning - with the lowest number of adult mosquitoes since May.
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 news has been all about the unseasonably warm weather lately. MMCD even made a stop by Fox 9 Morning on Monday to talk about how the unusual weather is affecting mosquitoes and ticks. Despite 80 degree temperatures last week that are carrying on into this week, mosquito activity has mostly abated for 2025.
According to MMCD Entomologist, Dr. Scott Larson, "While the unseasonable warmth means some mosquitoes are still lingering out there, the average number of human-biting mosquitoes per CO2 trap last week was only 14.42. That is the lowest level of mosquito abundance we have witnessed since May."
Below are maps showing all human-biting mosquitoes (left) and Culex mosquitoes (right) collected in CO2 and Gravid traps on September 22nd-23rd:
West Nile virus risk is decreasing, but it will remain a threat as long as some mosquitoes are still active
Most mosquitoes are gone for the year, so many people may be tempted to put the insect repellent into storage. Not so fast, says MMCD Vector Ecologist, Dr. Jordan Mandli. "[West Nile Virus]-infected birds continue to infect the few remaining active mosquitoes, prolonging transmission until we reach true quiescence, when mosquito activity ceases entirely," says Mandli. "From a public health perspective, this transitional period is critical for prevention. The misconception that 'mosquito season is over' can lead to reduced use of repellents and protective measures."
It's a great time of year for an evening bonfire or a fall hike, but please pack the bug spray if you are out during mosquito activity times!
2025 Mosquito Season Wrap-Up Next Week
We are done with widespread trapping for the year, but are still collecting data in some areas. Next week we will have our final update with a wrap-up and look back at the 2025 year in mosquitoes, ticks, and black flies.
