A customer recently told me that prior to using Mosquito Shield they would throw a “First Frost” party to celebrate the end of the mosquito season (they have since purchased new outdoor patio furniture). It is true that once temperatures hit below 50° or so we can expect relief from these pesky vampires. But where do they go? Do they don winter coats and get all snuggly under the tarp covering the woodpile, that hollow tree or animal burrow?
Well, yes, some do, in a sense. In Pennsylvania about 62 different mosquito species have been identified, and even among the handful of the most common they have different overwintering strategies.
Mosquitoes are like Bears!
Ok no not really, but they do something akin to hibernating called diapause- basically they find cool, dark protected hidey-holes and their development shuts down until Spring. The female of the common house mosquito, or Culex Pipiens start storing fat as winter approaches (so what else is new). According to entomologist David Denlinger “females that go into diapause probably have 10 times the fat accumulation than a non-diapausing mosquito has” (1) (sign me up for non-diapausing). Unfortunately this widespread-in-PA mosquito also has the “highest infection rate (for West Nile disease) of any species suggesting females serve as important overwintering reservoirs in PA” (2).
Others, among the most common “PA” mosquitoes like the Psorophora, and Aedes Vexans overwinter in the egg stage. They can lay their eggs in moist soil or that freezes and do not need to surface to breathe. And the Ochlerotetus j. japonicas larvae can be collected in any number of artificial containers, “tires, birdbaths, wooden and concrete barrels, porcelain bathtubs, toys and earthenware containers” (3).
For an exhaustive list of the Mosquitoes of Pennsylvania with distribution maps, click here.
The moral of the story is an underscore of what we already know: empty out containers of any kind & do whatever possible to ensure adequate drainage on your property. And call Mosquito Shield. If there are fewer mosquitoes on your property at the end of the season it stands to reason that there will be fewer for blooming foliage to welcome come spring.