Wasps are insects belonging to the order Hymenoptera, a diverse group that also includes bees and ants. These creatures are characterized by their distinct narrow waist and typically possess four membranous wings. For wasps, temperature plays a significant role, influencing their metabolism, behavior, activity levels, and overall survival.
Wasp Activity and Temperature Preference
Wasps are ectothermic organisms, meaning their internal body temperature is determined by the external environment. As ambient temperatures rise, their metabolic rates increase, leading to increased activity. Wasps are most active in warm weather, thriving in a range between 20°C and 30°C (68°F to 86°F). This optimal range allows them to efficiently forage for food, build nests, and reproduce.
During summer, warmer temperatures and abundant food contribute to increased colony growth and foraging. The warmth accelerates their reproductive cycles, leading to larger populations. As natural food sources become scarcer in late summer and early autumn, wasps intensify their search for sustenance, often bringing them into closer contact with human activities. This elevated activity and rapid development are a direct consequence of their metabolic processes operating more efficiently in warmer conditions.
How Extreme Temperatures Affect Wasps
While wasps thrive in warmth, extreme temperatures significantly impact their survival. When temperatures exceed 30°C (86°F), wasps seek shade and water to prevent overheating. Prolonged exposure to extreme heat can lead to dehydration, reduced activity, and mortality. Wasps can perish when temperatures reach approximately 44.9°C (113°F). Heatwaves can result in significant casualties within wasp populations, with larvae being particularly vulnerable.
Conversely, cold temperatures decrease wasp activity; below 20°C (68°F), wasps become sluggish. They enter a dormant state below 10°C (50°F), and most worker wasps die off as winter approaches. Fertilized queen wasps are the primary survivors, seeking sheltered locations to hibernate. During hibernation, their metabolic rate slows, enabling them to endure without food. Queen wasps can withstand temperatures as low as -15°C (5°F) within their protected overwintering sites.
Thermal Regulation Within Wasp Nests
Within their nests, wasps engage in collective behaviors to regulate temperature, important for protecting the developing brood. Maintaining a stable internal nest temperature is necessary for the proper development of larvae and colony health. One active cooling strategy is evaporative cooling, where they bring water droplets into the nest, and the evaporation lowers the temperature. This method can reduce the temperature within individual cells by approximately 8°C. Wasps can also fan their wings to cool the nest.
Wasps also utilize passive thermoregulation by selecting nest sites, opting for sun-exposed areas during cooler periods or shaded locations during extreme heat. The physical structure of the nest contributes to maintaining stable internal temperatures. High humidity levels within the nest also play a role in temperature stability.