Hornets, like many social insects, exhibit an annual life cycle that culminates in a shift as winter approaches. Their colonies, which thrive throughout the warmer months, undergo a transformation when temperatures begin to drop. This seasonal change is a fundamental aspect of their biology, ensuring the continuation of the species despite the harsh conditions of winter.
The Colony’s Annual Decline
As autumn progresses and colder temperatures arrive, most of a hornet colony perishes. Worker hornets, sterile females responsible for foraging, nest maintenance, and caring for the young, typically die off due to cold weather and dwindling food. Male drones, whose primary role is to mate with new queens, also perish as their purpose concludes. The original queen, who initiated the colony in the spring, also meets her end with winter’s onset.
Hornet nests are annual structures, constructed anew each spring and never reused. These papery nests often deteriorate or are abandoned by winter. Abandonment prevents disease and parasite buildup, ensuring new queens establish colonies in uncontaminated locations.
The Queen’s Winter Survival
While most of the colony perishes, the species’ future rests on newly emerged queens. In late summer or early autumn, the colony produces fertile males and new queens. After mating, these fertilized queens seek sheltered locations to overwinter, a process known as diapause. Common sites include protected crevices in tree bark, hollow logs, leaf litter, soil, or secluded spots within buildings.
During diapause, the queen’s metabolism slows, conserving energy and allowing her to survive months without food. This dormant state enables the queen to endure prolonged cold and scarcity. She relies on fat reserves accumulated prior to entering diapause to sustain her through winter. This adaptation helps the hornet persist across seasons.
New Beginnings in Spring
As spring arrives and temperatures rise, surviving queens emerge from dormancy. The timing of emergence can vary, but generally occurs from late March to early May, depending on the climate. Each queen then embarks on the solitary task of establishing a new colony. She searches for a suitable location, often including undisturbed areas like sheds, attics, or sheltered outdoor spaces.
The queen begins by constructing a small, initial nest, comprising a few cells. She gathers wood fibers, chews them, and mixes them with her saliva to create a paper-like material for the nest. Once initial cells are built, she lays her first eggs.
She then cares for these eggs and larvae, foraging and expanding the nest until the first worker hornets emerge. These workers then take over nest enlargement, food collection, and tending to broods, allowing the queen to focus solely on egg-laying.