A Pesky Problem
4:00 am
Sun September 22, 2013

Mosquito Madness, Even in Autumn?

Despite several nights of frost in the past week, some Northern Wisconsin residents are still plagued by the telltale buzz of mosquitoes.  How does a mosquito survive in cold temperatures?

Wisconsin is home to more than 50 varieties of mosquito.
Credit E. A. Goeldi

Common knowledge holds that once nighttime temperatures dip into the 30s, mosquito populations drop off.  But that didn’t seem to be happening last week.  Susan Paskewitz, a mosquito expert at the University of Wisconsin Madison, says it’s possible most of the still-active mosquitoes are newly formed.

“And it might actually be that that’s what you’re seeing – a pretty high population of those larvae just now emerging.  You get the larval stages in the water, and just a couple of transient nights of cold temperatures really aren’t gonna be enough to stop their development. ”

Paskewitz says water temperatures don’t change as quickly air temperatures.  She also points out the presence of mosquitoes could depend on the local mix of species.  Some are more cold tolerant than others.

“There are probably 53, 54 species of mosquito in Wisconsin, all with very different behaviors.  Adults of some species actually overwinter, and so they’re pretty good even as an adult at surviving very cold temperatures.”

One the bright side she says those varieties, though they may be alive, won’t usually be in feeding mode in the middle of winter.