What Happens to Mosquitoes in the Winter?

For those of us living in colder climates, there’s one bright spot in the frigid hellscape of winter. Mosquitoes fall back and retreat, pausing their bloodlust and obviating one's need for bite repellent. But where do they actually go? Florida? Can mosquitoes even survive in less-than-humid conditions?

According to Reader’s Digest, these nuisance insects have two strategies for coping with temperatures below 50°F. Males drop dead. (Though not because of the cold. After mating in the fall and living an average of 10 days, they’ve reached the limits of their usefulness and perish before the cold front comes in.) Females enter diapause, a kind of hibernation in which they find a hollow log or spot in the ground to burrow into and slow their metabolism. No matter how low the temperature drops, they can survive in this state for as long as six months. They don’t need water, either.

To prepare for this, females gain weight—up to 10 times their normal body weight—and wait for winter to pass. When the weather warms up, they emerge and head off in pursuit of blood to nourish their eggs. That’s where humans come in.

Of course, there’s never a guarantee winter will provide a vacation from mosquitoes. One neighborhood in Manhattan has long suffered from an infestation of Culex pipiens molestus, which has evolved to breed underground in the winter without needing to feed. The mosquitoes then infiltrate homes, leading to disgruntled residents being attacked in the cold months.