Wasps’ ability to fly is affected by cold temperatures, though it is not a simple yes or no answer. Their activity decreases significantly as temperatures drop, making them far less noticeable than during warmer months. The cold profoundly influences their physiology and behavior.
How Wasps Cope with Cold
Wasps are ectotherms, meaning their body temperature and metabolic functions are largely dependent on external environmental temperatures. As temperatures fall, their metabolism slows down considerably, impacting their overall activity. To generate heat for flight, wasps can shiver their flight muscles, a process known as thermogenesis. This allows them to warm up their bodies to a degree, enabling some movement or short flights. However, this ability has limitations, and sustained heat production becomes challenging in increasingly cold conditions.
The Science of Wasp Flight in Low Temperatures
The ability of wasps to fly is severely hampered by low temperatures. Most wasps find it difficult to fly at all once temperatures drop below 50°F (10°C). While they might still be able to move or crawl at lower temperatures, their characteristic buzzing flight is largely absent. Some species, like yellowjackets, may remain active until temperatures approach freezing, but their mobility is still significantly reduced.
What Happens to Wasps When Winter Arrives
As consistent cold temperatures arrive, typically in late fall or early winter, the vast majority of a wasp colony does not survive. Worker wasps, males, and the old queen die off, often due to a combination of cold temperatures and dwindling food sources. The survival of the species relies on the newly fertilized queens. These queens seek sheltered locations, such as under tree bark, in hollow logs, or within the cracks and crevices of buildings, to overwinter.
During this period, the queen enters a state of dormancy called diapause, which is similar to hibernation. In diapause, her metabolic rate slows significantly, allowing her to conserve energy and survive on stored fat reserves without needing to eat. Some queen wasps even produce a natural antifreeze, like glycerol, to prevent ice crystals from forming in their bodies, aiding their survival in freezing conditions. When spring arrives and temperatures rise, these queens emerge to establish new colonies, restarting the annual cycle.