Wasps are often a common sight during warmer months, leading many to wonder about their fate when winter arrives. The perception of wasps simply “freezing” when temperatures drop is not entirely accurate. While the majority of a wasp colony does indeed perish with the onset of cold weather, a select few individuals possess adaptations that allow them to endure winter, ensuring the continuation of their species.
Winter’s Impact on Wasp Colonies
As the colder season approaches, the vibrant activity of a wasp colony significantly diminishes. Most worker wasps and male wasps, known as drones, do not survive the winter; their annual life cycle means they are not equipped to withstand prolonged freezing temperatures. These individuals typically succumb to the cold or a lack of available food sources as autumn progresses. The entire colony, including the old queen, eventually dies off, leaving the nest empty. This annual demise of the vast majority of the colony is a natural part of the wasp life cycle, with only one individual prepared to face the winter months.
The Queen’s Winter Survival Strategy
The sole survivor of the winter is the newly fertilized queen wasp, produced in late summer or autumn. She enters a specialized state of physiological dormancy called diapause, which is comparable to hibernation in mammals. During diapause, the queen’s metabolic rate slows considerably, allowing her to conserve energy and survive without food for extended periods. To withstand sub-zero temperatures without cellular damage, the queen produces cryoprotectants, such as glycerol, within her body fluids. This natural “antifreeze” compound lowers the freezing point of her internal fluids and helps prevent destructive ice crystals inside her cells, enabling her to endure the cold without truly freezing solid.
Where Wasps Spend the Winter
For the fertilized queen to successfully navigate the winter, she must find a protected location where she can remain undisturbed. These overwintering sites, often called hibernacula, shield her from extreme cold, harsh winds, and predators. Common places include sheltered, secluded spots like under loose tree bark, within rotting logs, or buried in leaf litter or soil. Queens also frequently seek refuge in human-made structures, utilizing wall voids, attics, sheds, garages, and small crevices in buildings. The selection of a dry, insulated spot is important, as moisture can encourage fungal growth or lead to damaging ice crystal formation.
The Return of Wasps in Spring
As spring arrives and temperatures consistently warm, the surviving queen emerges from her overwintering site. Her emergence is often triggered when ambient temperatures reach about 10°C in shaded areas. Upon waking, her priority is to locate a suitable place to establish a new colony. She constructs a small, initial nest, often from chewed wood pulp, and lays the first batch of eggs. These eggs hatch into larvae, developing into the first generation of sterile worker wasps; once mature, they take over foraging and nest expansion, allowing the queen to focus solely on laying eggs and perpetuating the colony’s growth.