The welts that form after she leaves are an allergic reaction to this saliva. For most people, the swelling and itching subside after a few hours, but they can persist for days for an unluckily sensitive few. Scratching the bites only serves to spread the saliva, and can even lead to infection. Mosquitoes function best at 80 degrees Fahrenheit, become lethargic at 60 degrees, and fall into a stupor below 50 degrees. In tropical areas, mosquitoes are active year-round, but in northern Wisconsin, they must hibernate.
Some species have winter-hardy eggs that hatch with the spring thaw.
Others overwinter as adult females, mating in the fall, passing the winter in a state of torpor in an animal burrow, hollow log, or even in your basement, and immediately seeking a blood meal in the spring before laying their eggs and dying. A few species even spend the winters as larvae, buried in the mud beneath freshwater swamps. When winter ends, they complete their transformation into adult mosquitoes. Comments and questions about this web site can be E-mailed to Northland's web editor .