The common sight of insects swarming porch lights often leads to the assumption that all winged creatures, including wasps (like yellow jackets and paper wasps), are drawn to artificial illumination. Wasps possess sophisticated navigation and foraging strategies that differ significantly from nocturnal insects. Understanding why these daytime foragers appear near a light source requires examining the complex science of insect orientation.
Wasp Behavior and Reaction to Light
The interaction between an insect and light is known as phototaxis, classified as positive (moving toward light) or negative (moving away from light). Most social wasps, such as yellow jackets and paper wasps, are primarily diurnal, meaning their activity peaks during daylight hours. Unlike moths, which display strong positive phototaxis, these diurnal species do not possess an inherent biological drive to fly toward artificial lights at night. While this holds true for the majority, the European hornet is an exception. This species is crepuscular or nocturnal and is known to be attracted to light, temporarily disrupting its normal rest cycle.
Understanding Why Wasps Appear Near Light
The presence of a wasp near artificial light is usually a result of disorientation, not direct attraction. Wasps rely on celestial cues, such as the sun, to maintain a straight flight path over long distances. When a nearby artificial light is introduced, the insect attempts to use it as a substitute for the distant sun or moon. However, the light’s proximity causes a constant shift in the angle of the source, forcing the wasp into a spiraling or circling flight pattern.
A significant factor drawing wasps to lights is the abundance of prey that are genuinely attracted to the illumination. Wasps are predators that feed insects to their larvae, and artificial lights create concentrated feeding opportunities by attracting numerous moths, flies, and beetles. The light fixture becomes a hunting ground. The wasp is not seeking the light, but rather the congregation of food items the light has inadvertently gathered.
Light fixtures can also offer a convenient nesting site or a source of warmth for social wasps. Paper wasps often construct their open, umbrella-shaped nests underneath eaves and directly behind outdoor light fixtures. These areas provide protection from rain and wind, and the residual heat produced by certain bulbs can be an additional incentive for them to establish a colony.
Practical Prevention and Deterrents
Minimizing the presence of wasps involves addressing secondary attractants and reducing the confusing effects of the light. Changing the type of bulb used in outdoor fixtures can significantly decrease the number of insects, including the wasps’ prey, that gather. Warm-colored lights, particularly those in the yellow or amber spectrum, are less disruptive to insect vision. They attract fewer flying insects compared to bright white or blue-toned lights that emit more UV radiation. Switching to dedicated “bug lights” or sodium vapor lamps helps reduce the overall insect population.
It is productive to remove or secure common food sources near outdoor lighting, as foraging wasps are drawn to sweet substances and protein. Wasps frequently scavenge for food for their maturing colonies in late summer, making food sanitation especially important.
Food Source Removal
This involves promptly cleaning up spills from sugary drinks, ensuring trash cans are tightly lidded, and removing fallen, overripe fruit from the ground.
Finally, inspect the areas surrounding light fixtures and entry points to prevent nesting. Wasps build nests in small crevices or voids. Sealing small gaps around window frames, door jambs, and the base of the light fixture with caulk can prevent a queen from establishing a new colony. Regularly checking sheltered spots like eaves and the backs of fixtures for small, early-stage nests allows for safe removal before the colony grows large.