This article was published originally on 6/27/2012
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 mosquito populations are monitored using New Jersey Light Traps set around the state.
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. Click on "County" on the left side of the page to see individual county data. Click "Year" to see historical data comparing yearly mosquito population trends.
Summary for the week of June 22, 2012: Trap results from around the state show that mosquitoes are relatively inactive right now. This is one of our slowest years in recent memory. As you can see from the data on the Iowa Mosquito Surveillance website mosquitoes are even less active now than they were last year at this time, and this is stating something because last year was memorably low in mosquito abundance (aside from the flooded western Iowa situation).
The statewide relative lack of rainfall has reduced mosquito activity considerably, but keep your eye on the weather. Our colleagues in Des Moines have told us that there are some larval sites that have held water for years and years but are now dry. In fact, there are some streams that have lost enough water that they are now still. We wonder if this will encourage breeding among the stagnant water breeders, like Culex. Even if this happens, it would not contribute much to noticeable mosquito levels.
Many have asked if last winter's warm weather would positively influence mosquito populations. Results so far show winter weather has had no bearing. Mosquito populations are dependent on the perfect storm of conditions with temperature and rainfall and, just as importantly, the duration of the two. The weather has not lent itself to a mosquito problem. Had the temperature increased steadily and consistently through spring and summer, and had it been accompanied by strong bouts of rainfall, we could have seen an earlier rise in the mosquitoes that plague our lives, but we are in the midst of a comfortable year so far.