Weekly Update – September 4th – Mosquito Numbers Declining as We Enter September
September 11, 2024
Mosquito numbers are almost precisely in line with the 10-year average as we head into the last weeks of surveillance.
We are preparing to wrap up the 2024 season at MMCD.
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.
Two surveillance updates in one week? Thanks to dryer conditions and lower counts of Culex mosquitoes, our lab was able to get a jump on this week's trap counts and send the weekly surveillance update a couple of days early. We love when the weather cooperates!
In his weekly update to staff, MMCD Entomologist Dr. Scott Larson says "we are almost exactly at the 10-year average, so things are back to normal? I think so. The season seems to be ending where it should. There were mostly floodwater mosquitoes collected this week. The cattail adults are almost all gone. The late season mosquitoes are here (Culiseta inornata and Uranotaenia sapphirina). There was only 1 spring Aedes collected this week in the CO2 traps, and I’m impressed this one hung on so long."
Most of the effort of field staff this time of year is to monitor for cattail mosquitoes. This unique species hatches in late summer and overwinters as larvae before emerging from the water as adult mosquitoes around the beginning of July the following year. Learn more about MMCD's cattail mosquito program.
Here are the maps from Monday-Tuesday, September 9th-10th:
