Yellow jackets are social wasps that become increasingly noticeable during the late summer and early fall as they forage for carbohydrates to sustain their colony. The way yellow jackets navigate their environment and locate food sources is heavily influenced by the colors present in their surroundings. This visual reliance means that simple choices, such as clothing or trap color, can significantly affect their level of interest.
The Core Attraction Colors
Yellow jackets are strongly drawn to colors that mimic the appearance of rewarding food sources in nature, which centers primarily on the color yellow. This attraction is a conditioned response, as many nectar-rich flowers that provide the carbohydrates they seek often feature yellow pigments or highly contrasting patterns. Bright yellow objects, whether they are picnic blankets, clothing, or food packaging, can be mistaken for a potential meal, prompting the wasps to investigate closely.
White is another highly attractive color, especially when presented as a bright, high-contrast element against a darker background. Wearing light-colored clothing can inadvertently create a visual beacon, drawing the attention of passing wasps who are actively seeking out anything that stands out in their field of view.
Bright blue colors are also known to catch a yellow jacket’s attention, although not as consistently as yellow. The combination of bright yellow and light blue, often seen in floral patterns or high-visibility gear, can create a particularly inviting visual target.
Colors That Deter Yellow Jackets
Choosing the right colors for outdoor activities can make a person less visible and therefore less interesting to foraging yellow jackets. Colors that do not reflect the specific wavelengths of light they perceive as food are generally ignored. This includes the darker end of the color spectrum, such as navy blue, deep green, and black.
Neutral earth tones like khaki, tan, and muted browns also provide a degree of camouflage, helping people blend into the natural environment. These colors lack the brightness and contrast that yellow jackets associate with flowers or exposed food.
One of the least attractive colors to yellow jackets is red, which they cannot perceive as a distinct color. The physiology of their vision means that red appears as a muted, dark, or black tone, making it visually insignificant to them. While no color actively repels them, red clothing is far less likely to be investigated than yellow or white.
How Yellow Jacket Vision Works
The strong preference yellow jackets exhibit for certain colors is rooted in the unique structure of their visual system. Like many insects, yellow jackets possess compound eyes, which are composed of thousands of individual light-sensing units called ommatidia. This structure provides them with a wide field of view and an exceptional ability to detect motion, which is useful for hunting prey and avoiding threats.
Their color vision is trichromatic, meaning they primarily rely on three photoreceptor types, but their sensitivity is shifted toward the shorter wavelengths of the light spectrum. Unlike humans, who see red, green, and blue, yellow jackets perceive ultraviolet (UV) light, blue, and green. This UV sensitivity is particularly significant, as many flowers that are white or yellow to the human eye have distinct UV patterns that act as nectar guides for insects.
Because they lack the necessary photoreceptors, yellow jackets cannot register the color red, which falls at the long-wavelength end of the spectrum. To a yellow jacket, red appears simply as a shade of black or gray, which does not trigger the foraging response associated with bright flowers.
Using Color to Optimize Trapping
The knowledge of yellow jacket visual preferences is directly applied in pest control, specifically in the design and placement of traps. Commercial yellow jacket traps are nearly always colored yellow, often with white or clear components, to exploit their attraction to these specific hues. The color functions as the initial, long-distance lure, drawing the wasps to the vicinity of the trap before the scent of the bait takes over.
Trap placement should also consider the visual environment, as yellow jackets are more likely to encounter traps placed in bright, sunny areas. Research suggests that yellow jackets orient their flight paths toward sunny locations, making traps positioned in direct sunlight more effective at intercepting them than those in the shade.
While the trap body’s color serves to visually attract the wasps, the specific color of the bait itself is less of a factor than its scent. However, some anecdotal evidence suggests that in DIY traps, yellow jackets may show a preference for darker-colored liquids, such as red wine, over white. This preference is likely due to the fermentation products and sugar content of the bait, rather than the color itself.