Wasps, often seen buzzing around during the warmer parts of the year, are social insects that organize into complex colonies. As the vibrant hues of summer fade and autumn’s chill sets in, many people wonder about the fate of these common insects. Their seemingly sudden disappearance from the landscape as temperatures drop sparks curiosity about their survival strategies during the colder months.
The Annual Cycle of a Wasp Colony
The life of a social wasp colony begins in spring with a single queen. She emerges and starts building a small nest from chewed wood fibers. She then lays her first batch of eggs, which hatch into larvae that she feeds and cares for until they develop into adult worker wasps.
As summer progresses, these sterile female worker wasps take over the duties of foraging for food, expanding the nest, and caring for subsequent broods. By mid to late summer, a wasp colony reaches its peak, housing thousands of individuals, with nests growing large. Towards late summer and early autumn, the colony shifts its focus, producing a new generation of fertile males and new queens.
Winter’s Impact on the Colony
As winter approaches and temperatures begin to fall, the vast majority of the wasp colony perishes. Worker wasps and male wasps are particularly susceptible to the cold. They often die off with the first hard frosts and sustained cold temperatures, below 50°F, which impairs their ability to fly and forage effectively. The old queen, having completed her reproductive cycle, also dies. This natural cycle means that the expansive nests seen during summer are abandoned and are not reused in subsequent years.
Only the newly emerged, fertilized queen wasps survive the winter. Their survival is contingent on finding suitable overwintering sites and entering a state of dormancy. Various factors contribute to the demise of the remaining colony members. A small percentage of these new queens successfully endure the winter.
Queen’s Winter Refuge
The newly mated queen wasps seek out sheltered and insulated locations to spend the winter months. These sites, known as hibernacula, offer protection from extreme cold, predators, and moisture. Common overwintering spots include crevices under loose tree bark, within hollow logs, and in protected areas of human structures such as attics, wall cavities, sheds, and garages. They may also find refuge underground in old rodent burrows or within piles of leaves.
Once settled, the queen enters a state of dormancy called diapause, which significantly slows her metabolism. During diapause, her energy consumption is drastically reduced, allowing her to survive on stored fat reserves. Some queen wasps can even produce natural antifreeze compounds in their bodies, preventing ice crystals from forming in their tissues during extremely cold conditions.
Emergence and New Beginnings
With the arrival of spring and rising temperatures, the overwintering queen wasps awaken from diapause. Their first instinct upon emergence is to find food to replenish their energy reserves. Following this, they begin searching for a suitable location to establish a new nest.
The queen then starts constructing a small nest from wood pulp, laying her initial batch of eggs. These first offspring will develop into the sterile worker wasps that will help expand the nest and forage for food. This marks the beginning of a new colony cycle, continuing the annual rhythm of wasp life.