Wasps are insects whose activity levels vary with environmental conditions and time of year. This article explores the daily, seasonal, and weather-related factors that influence wasp activity, leading to periods when they are least active.
Daily Rhythms
Wasp activity follows a daily pattern, largely influenced by light and temperature. During daylight hours, particularly from mid-morning to late afternoon, wasps are most active. They spend this time foraging for food, gathering materials for their nests, and expanding their colonies.
As dusk approaches and light levels diminish, wasp activity decreases. Wasps return to their nests at night, becoming inactive. This reduced activity is primarily because most wasp species rely on visual cues for navigation and foraging, and their vision is limited in low-light conditions. Their metabolism also slows with dropping evening temperatures, making sustained flight and foraging less efficient.
Seasonal Shifts
The annual cycle of wasp activity varies significantly throughout the year. During winter, wasp activity is at its lowest. Most worker and male wasps die off as cold weather sets in, and only fertilized queen wasps survive by entering dormancy or hibernation in sheltered locations like attics, wall voids, or underground.
In spring, as temperatures begin to rise, queen wasps emerge from hibernation and start building a new nest and laying eggs. Activity gradually increases through late spring and early summer as the colony grows and worker wasps hatch, taking on duties like nest expansion and foraging. Wasp activity peaks in late summer and early autumn when colonies reach their largest populations, often numbering in the thousands. During this period, foraging is intense to sustain the large colony, and wasps may appear more aggressive as food resources become scarcer. Activity then declines sharply as colder weather returns, leading to the demise of most of the colony, except for new queens destined to hibernate.
Weather’s Influence
Specific weather conditions impact wasp activity, often causing them to become less active. Temperature is a primary factor, as wasps are ectothermic, meaning their body temperature and activity levels are directly tied to the surrounding environment. Wasps become sluggish and less active when temperatures drop below 10°C (50°F), finding it difficult to fly. Activity is optimal between 20°C to 30°C (68°F to 86°F), while temperatures above 30°C (86°F) may cause them to seek shade and water, leading to a slight decrease in activity. Temperatures below freezing, around 0°C (32°F), are lethal for most wasps, and temperatures exceeding 40°C (104°F) can also be fatal due to dehydration and stress.
Precipitation, especially heavy rain, also reduces outdoor wasp activity. Wasps seek shelter in their nests during rainfall because water droplets can add weight to their bodies and disrupt the aerodynamics of their flight. Rain also reduces visibility, making navigation and foraging difficult, and can lower the ambient temperature, slowing their metabolism. While wasps can fly in light rain, they avoid foraging in such conditions due to these challenges.
Strong winds can hinder wasp activity. High wind speeds create a drag force on their wings and bodies, making sustained flight challenging and disorienting. This physical hindrance makes it more difficult for wasps to forage for food and gather materials for nest building. Wasps are less likely to be active outdoors during windy conditions, often seeking shelter to conserve energy.