Wasps are common during warmer months. Their seasonal activity and what happens to them as weather changes often raise questions. Understanding their natural cycle explains why they are more noticeable at certain times, defining “wasp season.”
The Wasp Annual Cycle
The life cycle of social wasps, such as yellowjackets and hornets, begins in spring with a single queen. After emerging from her overwintering spot, the queen builds a small nest from chewed wood fibers mixed with saliva. She then lays her first batch of eggs within this initial structure.
These first eggs hatch into larvae, which the queen feeds with protein-rich insects. Once mature, these larvae pupate and emerge as sterile female worker wasps. The worker wasps then take over expanding the nest, foraging for food, and caring for more larvae, allowing the queen to focus solely on laying more eggs. Throughout the summer, the colony grows rapidly, with the worker population sometimes reaching thousands.
When Wasp Activity Declines
Wasp activity gradually declines as environmental conditions shift in late autumn. This reduction is triggered by dropping temperatures and a decrease in available food sources. When temperatures fall to 50° Fahrenheit, worker wasps become less active, eventually losing the ability to fly below 40° Fahrenheit.
As the season progresses, the colony’s focus shifts from producing more workers to raising new reproductive individuals: future queens and males. Once these new queens and males mature and mate, the need for worker wasps to forage for larvae diminishes. With fewer larvae to feed and natural food sources becoming scarce, worker wasps search for sugary foods, often bringing them into closer contact with humans.
The Fate of Wasp Colonies
As cold weather sets in, most of the wasp colony perishes. Worker wasps, having completed their life cycle and with dwindling food resources, die with freezing temperatures. The old queen also dies, often within the nest.
Only the newly emerged, fertilized queens survive the winter. These new queens seek sheltered locations, such as under tree bark, in hollow logs, in attics, or within wall voids, where they enter a state of dormancy called diapause. They conserve energy during this period, relying on stored fat reserves. The old nest, now abandoned, is rarely reused by the surviving queens, who build new nests the following spring to start the cycle again.