Hornets, large social wasps, often spark questions about their activities during colder months. Many wonder if these insects simply disappear or enter a state of inactivity when winter arrives. This query stems from the noticeable absence of hornet nests and foraging individuals once temperatures drop. Understanding the hornet’s annual cycle provides clarity on their survival strategies through the changing seasons.
The Fate of Hornet Colonies in Winter
As autumn progresses and temperatures fall, the vast majority of a hornet colony does not survive. Worker hornets and male drones typically perish with the onset of cold weather and dwindling food supplies. Hornet nests are annual structures, built anew each spring and not reused in subsequent years. The existing colony dies off by late autumn or early winter. This seasonal demise is not a true dormancy for the entire colony, but rather a natural end to their life cycle.
The old queen also typically dies before winter. Unlike honeybees, hornets do not store large quantities of food to sustain the entire colony through cold periods. Consequently, the large paper nests become inactive and abandoned, often seen hanging empty in trees or sheltered locations.
The Queen’s Winter Survival
While the rest of the colony perishes, newly fertilized queens are the sole survivors. They enter a state known as diapause, a physiological dormancy that allows them to endure the cold and lack of food. During diapause, the queen’s metabolism slows, conserving energy until more favorable conditions return.
These overwintering queens seek sheltered locations to pass the winter months, protected from the elements and predators. Common overwintering sites include loose tree bark, rotting logs, soil, leaf litter, and crevices. They may also find refuge in human-made structures like attics, wall voids, sheds, or garages. This survival mechanism of the fertilized queen highlights her role in the hornet life cycle.
New Colony Formation in Spring
With the arrival of spring, rising temperatures signal the end of diapause for the overwintered queens. Each queen emerges from her dormant state and begins establishing a new colony. She searches for a suitable, protected location to construct her new nest. Hornets do not return to old nests, instead building a new structure each year.
The queen constructs a small initial nest from chewed wood pulp and saliva, forming the characteristic paper-like material. She then lays her first batch of eggs, which become the first generation of worker hornets. Once these new workers mature, they take over foraging for food, expanding the nest, and caring for new generations, allowing the queen to focus on laying more eggs. This process restarts the annual hornet colony cycle.