Weekly Update – June 20th – Adult Mosquito Numbers Decline for 2nd Week
June 26, 2023
Weekly Update – July 5th – Adult Mosquitoes Drop Lower than 2022; Cattail Peak is Past
July 11, 2023
Mosquito numbers continue to decline as we head into July.
Mosquito numbers decline once again as we approach drought levels in the Twin Cities.
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.
Despite a few instances of widespread rain throughout the Twin Cities, overall adult mosquito numbers continue to decline as we head into the first week of July. The drought monitor has the majority of the metro under "moderate drought" conditions as of last week and there hasn't been enough rain the past several days to change that.
According to MMCD assistant entomologist Dr. Scott Larson, "we are currently collecting [around] 500 mosquitoes less per trap than the 10-year average. You know how Aedes vexans are normally our most abundant mosquito? Not this year. There are way more Aedes cinereus so far and even more spring Aedes than Ae. vexans mosquitoes."
Here are the mosquito trap counts from last Monday, June 26th:
Mosquitoes test positive for West Nile virus in Anoka, Scott, and Ramsey Counties.
As we head into the hot months of July and August, the risk for many mosquito-borne diseases like West Nile virus increases. This past week five of 51 samples of mosquitoes tested positive for West Nile virus according to MMCD Vector Ecologist Kirk Johnson. Three positive samples came from Anoka County with one each in Scott and Ramsey Counties.
Ensure you are protecting yourself from mosquito-borne disease by using bug spray, wearing long, light, and loose clothing, and avoiding the peak feeding times of dawn and dusk.
In national news, there have been locally transmitted cases of mosquito-borne malaria in Florida and Texas for the first time in 20 years. Minnesota has vector species that are capable of transmitting malaria, but the risk is very low. Here is more from KARE 11 and MMCD staff Kirk Johnson and Diann Crane:
