Insect Update – Week of July 26th – More West Nile Virus Activity Found

Results from the July 26th surveillance show that while overall mosquito number remain unseasonably low, West Nile virus vectors are present

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.

We still haven't had much in terms of rain over the past several weeks, which means that mosquito numbers are still trending far below average for the end of July. However, we continue to collect species that can vector West Nile virus in our weekly traps and last week another sample in Ramsey County tested positive for the disease. Ramsey county currently has the most activity for West Nile virus with 6 of the 8 mosquito pools that have tested positive for the virus being collected there. The other positive pools came from Dakota and Hennepin counties.

Residents are advised to lower their risk of mosquito-borne disease by wearing insect repellent and avoiding peak feeding times of dusk and dawn. With lower annoyance mosquitoes, people may feel less inclined to take precautionary measures, but Minnesota is heading into the peak time of year for West Nile virus transmission.

Here are the mosquito trap counts from last Monday: