Wasps are a common sight in warmer months, often sparking curiosity about their disappearance as seasons change. Understanding when and why these insects vanish involves exploring their annual life cycle and the environmental factors that influence it.
The Annual Wasp Cycle
The annual cycle of a social wasp colony begins in spring with a single queen. After emerging from hibernation, she establishes a new nest, often in sheltered locations like attics, eaves, or underground burrows.
The queen constructs an initial paper-like nest from chewed wood fibers mixed with her saliva, lays her first batch of eggs, and cares for the developing larvae. Once these first offspring mature into sterile female worker wasps, they take over the tasks of nest expansion, foraging for food, and caring for subsequent broods.
Throughout summer, the colony grows rapidly, with the queen continuously laying eggs, sometimes hundreds per day. The colony reaches its peak population in late summer or early autumn, with thousands of individuals. Towards the end of this period, the queen produces a final generation of reproductive individuals: new queens and male wasps. These new queens and males leave the nest to mate.
Environmental Triggers for Decline
The decline of wasp activity in late autumn is primarily driven by changing environmental conditions. Dropping temperatures directly affect wasp metabolism and activity levels; temperatures below 50-60°F can hinder their ability to fly and forage effectively. As the days shorten, reducing daylight hours, this also cues biological changes within the wasp colony.
A significant factor in their decline is the scarcity of food sources. In early summer, worker wasps primarily hunt insects to feed protein-rich larvae, which in turn secrete a sugary liquid that adult wasps consume. By late summer and early autumn, as the queen slows egg production and fewer larvae are present, this internal sugar supply diminishes. Wasps then increasingly seek external sugar sources, such as ripe fruit, nectar from late-flowering plants, and human food waste, which become less available as the season progresses. This combination of cold, reduced daylight, and dwindling food supplies stresses the colony, contributing to its eventual demise.
The Fate of the Colony
As environmental conditions deteriorate, the wasp colony perishes. Worker wasps die off with the onset of cold weather and lack of food. Male wasps also die after mating. The older queen dies.
Only the newly fertilized queens from the final generation survive the winter. These new queens leave their birth nest and seek sheltered locations to overwinter, entering a state of inactivity called diapause. Common hibernation spots include under tree bark, in rotting logs, within wall cavities, attics, or other protected crevices, where they remain until spring.
The old nest is abandoned and not reused. New queens construct new nests in spring to begin the cycle anew.