Below is the summary of recent mosquito activity in Iowa from the ISU Medical Entomology Laboratory. Mosquito surveillance data can be viewed online at mosquito.ent.iastate.edu
Mosquito activity has continued to decline for the past few weeks at all mosquito surveillance sites around the state. This is particularly true of Aedes (floodwater) species, which thrive in ditches and other temporary water impoundments that occur following rainfall. Aedes vexans is still the most common mosquito in our samples but other human-biters, Ae. trivittatus and Ae. sticticus, are also common but to a much lesser extent.
Culex species, the important vector mosquitoes for West Nile virus (WNV) in Iowa, seem to thrive at this time of year. As Aedes breeding sites dry up, Culex mosquitoes are able to find breeding habitat in smaller, more permanent water bodies such as buckets and barrels. Even the Culex species that breed in more natural waters, like Cx. erraticus, are becoming common now. As we see from year to year, this is the time of greatest Culex diversity in Iowa. Thankfully, only a couple of these species harbor WNV; those species are Cx. pipiens and Cx. tarsalis. Again, these mosquitoes do not attain the abundance levels that floodwater species do, but they impose a danger on human health nonetheless.
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