Wasps and bees employ diverse strategies to endure winter’s cold temperatures and scarce resources. Many enter a state of dormancy or significantly alter their activity levels to survive. These survival mechanisms vary depending on the species, reflecting adaptations to environmental challenges.
Honey Bee Winter Survival
Honey bee colonies remain active through winter, unlike those that truly hibernate. When temperatures drop below approximately 50-57 degrees Fahrenheit (10-14 degrees Celsius), honey bees form a tight “winter cluster” inside their hive. Bees on the outer layers are tightly packed to insulate the core, where the queen and any remaining brood are kept warm.
Bees generate heat by rapidly vibrating their flight muscles, essentially shivering, which raises the cluster’s temperature. The core can maintain around 91-97 degrees Fahrenheit (33-36 degrees Celsius), especially if brood is present. Worker bees continuously rotate positions from the cooler outer layer to the warmer interior, ensuring no single bee becomes too cold. Throughout winter, the colony relies on stored honey as their primary energy source, moving the cluster slowly across combs to access provisions.
Bumble Bee Winter Behavior
Bumble bees, unlike honey bees, do not overwinter as an entire colony. Their annual life cycle concludes with the onset of cold weather; worker bees, males, and the old queen all perish.
Only new, mated queens survive to establish the next generation. These queens seek sheltered locations to spend winter in a state of dormancy, known as diapause. Common overwintering sites include soft soil, leaf litter, rotting logs, or under rocks, often just a few inches underground. During diapause, the queen’s metabolism significantly slows, conserving energy and allowing her to survive on fat reserves accumulated in late summer and early fall. She emerges in the spring, often among the first bees to appear, to forage and begin building a new nest.
Social Wasp Winter Behavior
Social wasps, such as yellowjackets and hornets, follow a winter survival pattern similar to bumble bees. Their colonies are annual, meaning most of the colony—including worker wasps, males, and the old queen—die off with cold temperatures.
Only new, mated queens survive winter by entering a state of dormancy or hibernation. These queens seek secluded, protected locations for their overwintering period. Typical sites include crevices in tree bark, under leaf litter, in hollow logs, or within sheltered human-made structures like attics and wall voids. During this time, their metabolism is greatly reduced, and they remain inactive until spring. When warmer weather returns, these queens emerge to find suitable nesting sites and establish new colonies.
Solitary Bee and Wasp Winter Strategies
Solitary bee and wasp species, representing the majority of bee and wasp diversity, employ diverse winter strategies as they do not form social colonies that overwinter.
For many solitary species, adult bees or wasps complete their life cycle by late summer or fall. Their survival through winter often occurs in an immature stage within their protected nests.
Many solitary bees and wasps overwinter as larvae or pupae inside individual cells of their nests. These nests can be found in various locations, such as hollow plant stems, burrows in the soil, or tunnels in wood. The larvae or pupae remain in a state of suspended development, or diapause, protected by the nest structure and provisioned with food. Some solitary bee species, particularly those that emerge early in spring, may overwinter as adult females within a cocoon, ready to emerge when temperatures rise. Emergence as adults typically occurs in the spring or summer, when conditions are favorable for foraging and reproduction.