Peak-a-boo? Where are you?
Where do mosquitoes go during the winter months?
Mosquitoes are cold-blooded creatures and do not generally bite in temperatures below 50F. In Georgia, some adult mosquitoes become inactive with the onset of cold weather and enter into hibernation before the first frost. Other mosquitoes die in the fall but have winter-hardy eggs, which hibernate as embryos.
Some species of mosquitoes die off when the weather turns cold, leaving only eggs, which lie on the ground like seeds, waiting for warmth and spring rains to hatch and produce a new generation. Except in the warmest part of their range, these adult mosquitoes actually do only live in the summer and disappear in winter.
Other species survive cold weather by hibernating. Mosquitoes that belong to the genera Anopheles, Culex and Culiseta hibernate, and so do some other less common types in the United States.
It’s hard to believe that these fragile-looking creatures can survive freezing temperatures.
J. Turner Brakeley, who owned a cranberry plantation up north in New Jersey, became fascinated around the turn of the 20th century with studying mosquitoes in the cold. Brakeley discovered a new species with a unique cold-weather survival strategy, the pitcher-plant mosquito (Wyeomyia Smithii) but he also found and described hundreds of ordinary hibernating adult mosquitoes, alive and well in the midst of a New Jersey winter.
Brakeley found mosquitoes, hiding outdoors in the sheltered areas of banks that overhung creeks, amid exposed tree roots, and in holes in the ground left by moles, mice and other animals, as well as in hollow trees.
Around human habitation, they hid in cellars of both barns and houses, where the underground temperature stayed warmer than the outside area. He also noticed them in vacant houses or buildings, or among boxes and other stored junk.
If they could find a partially heated space, such as a cellar in a heated home, they would fly away if he disturbed them. If they needed to survive where the temperature was truly cold, they went into full hibernation and he could pick them up or knock them loose so they fell to the ground.
To survive the cold, the mosquitoes took a position Brakeley called the “hibernation squat,” bending their legs and tucking their body close to the surface they sat on. They may have been trying to absorb some heat from the surface, since they’re cold blooded and can’t make their own body heat. He found thousands of mosquitoes hibernating in homes and outbuildings around the cranberry bogs, some in the cellars, others squatting on the walls or ceilings of empty buildings.
Since they don’t eat during the winter, they add weight in the fall by switching from blood to food with more sugar, such as rotting fruit or nectar, and can double their weight. Scientists have recently discovered what signals them to change their diet.
Some mosquitoes can stand the cold better than others and don’t need to hibernate where winters are mild, or will come out of hibernation when the weather warms even a little in winter, or will hatch in the spring while snow is still on the ground. They’re all usually nicknamed “snow mosquitoes,” though they belong to several different species
For more interesting known facts about mosquitoes visit MosquitoSquad.com
by Jeannie Moreira, Mosquito Squad of Duluth-Lawrenceville 770-271-1833