Discovering mosquitoes buzzing around when snow is still on the ground can be surprising, challenging the common perception of these insects as purely warm-weather pests. The term “snow mosquito” refers to several species of cold-tolerant mosquitoes. These insects are among the first to become active as winter transitions into spring, signaling the beginning of the insect season long before other mosquito species emerge.
Identifying Snow Mosquitoes
“Snow mosquito” often refers to species within the Aedes genus, such as Aedes communis or Aedes pullatus. These insects measure between 5 to 6 millimeters (0.19 to 0.23 inches) in length, comparable in size to common summer mosquitoes. They have scaly bodies that appear brown or black, sometimes adorned with lighter scales of white, gray, or yellow. While their appearance is similar to other mosquitoes, they can seem larger and more sluggish in movement compared to their warm-weather counterparts.
Habitat and Emergence
Snow mosquitoes are found in northern regions and at higher elevations, including parts of the United States, Canada, and Alaska. Their preferred breeding grounds are temporary pools of water, often called vernal pools, which form from melting snow and spring rains. These woodland pools provide the aquatic environment for their early development. As temperatures rise above freezing in late winter or early spring, often in March or April, these mosquitoes begin to emerge.
Unique Life Cycle and Survival
These mosquitoes have adaptations to survive freezing conditions. Many species overwinter in a dormant state, either as eggs laid in moist soil or under ice, or as larvae submerged in cold water. When snow melts, water triggers eggs to hatch, and larvae rapidly develop in the cold meltwater. Some species, like Culiseta alaskaensis, overwinter as adults, tucked away in sheltered spots such as leaf litter or beneath loose tree bark. Their bodies can produce glycerol, a carbohydrate that acts as a natural antifreeze, preventing ice crystals from forming inside their cells, allowing them to survive temperatures well below freezing.
Behavior and Feeding Habits
Upon emergence, snow mosquitoes primarily aim to mate and continue their species. Male snow mosquitoes feed exclusively on plant nectar and juices for energy. Female snow mosquitoes also consume nectar, but many species require a blood meal for egg production. While some female snow mosquitoes may bite humans, many species primarily seek blood from other mammals or birds. These early-season insects also serve as an initial food source for various animals, including birds and fish.