This article was published originally on 8/9/2013
Below is the summary of mosquito activity in Iowa from the ISU Medical Entomology Laboratory. Mosquito surveillance in Iowa has been ongoing since 1969. During the summer months, the Iowa State University Medical Entomology Laboratory, in cooperation with the Iowa Department of Public Health and the University of Iowa Hygienic Lab, monitors mosquito populations and mosquito-borne diseases in Iowa.
The Iowa mosquito collection data for the year are available online at the Iowa Mosquito Surveillance website. The statewide average mosquito counts by week (including a comparison to last year's mosquito activity) are shown.
Summary for the week of August 5, 2013
Mosquito numbers remain very low across the state, which is a very comfortable situation for people. However, the major West Nile Virus vector species, Culex pipiens and Culex tarsalis, are able to maintain a baseline (albeit low) levels of abundance throughout dry periods like this, so the threat of WNV exposure is still present. The floodwater species, on the other hand, are not nearly as common as they were in early summer as is evident in the graph below.
It's not too late to see a resurgence of mosquitoes this year. Back in 2007, significant flooding events in eastern Iowa in August resulted in extreme mosquito booms in late August and early September. That's also when our exotic invader, Aedes japonicus, gained a strong foothold throughout the state. What happens from here on out in 2013 will depend on rainfall; if you receive enough rain to result in consistently-standing water, you may expect mosquitoes to become active a couple of weeks later.
Remember that we are encountering WNV-positive mosquitoes and chickens at this time of year. As soon as we know of an infection in your area, we will let you know. In that vein, make sure that you keep up your source reduction efforts by eliminating sources of standing water where mosquitoes lay eggs. This is especially important because our major WNV vectors are "container-breeders," which means that they prefer to lay eggs in the containers that are common on public property and on everyone's lawns. Remember that insect repellent with DEET is effective at warding off adult mosquitoes.
Mosquito trap catch data from the ISU Medical Entomology Laboratory, August 8, 2013.