Mosquitoes are a nuisance for many people, especially in the warmer months. Their bites can leave itchy welts on the skin and some species can transmit dangerous diseases like malaria, yellow fever, dengue, Zika, and West Nile virus. Finding ways to avoid mosquito bites is therefore important for comfort and health. One question that often comes up is whether mosquitoes are attracted to or repelled by certain colors of light. In this article, we’ll explore what is known about mosquito vision and light preferences to determine if there are light colors that deter mosquitoes.
How Mosquitoes See Light and Color
Mosquitoes have very different eyes than humans. They have compound eyes made up of thousands of tiny optical units called ommatidia. Each ommatidium acts like a separate photoreceptor picking up one small facet of the mosquito’s field of vision. The mosquito’s brain then compiles all of these individual signals into one composite image. This gives the mosquito a very wide field of view in order to detect potential hosts and threats. However, their vision is much less acute than human sight.
Mosquitoes can see colors ranging from ultraviolet to red wavelengths. Certain wavelengths stand out more to them because of the sensitivities of their photoreceptor cells. Mosquitoes are particularly sensitive to ultraviolet (UV) light as well as shorter wavelengths in the violet-blue range. Longer wavelengths like red and infrared are less visible to them. Mosquitoes also see brightness differently. They are especially drawn to heat and CO2 sources like warm-blooded animals. Their eyes contain receptors that detect small temperature variations better than humans can.
Do Mosquitoes Prefer Dark Colors?
A common belief is that mosquitoes are more attracted to dark colors like black when seeking hosts. However, multiple studies have shown this is not true. Mosquitoes do not have preferences for landing on darker clothes or surfaces. In scientific experiments, mosquitoes landed randomly on differently colored clothes or targets without any statistically significant preference. This makes sense given what we know about mosquito vision. They have excellent motion detection but do not rely heavily on color distinctions for host-seeking.
Ultraviolet Light as a Mosquito Deterrent
Although mosquitoes do not prefer dark over light colors, some research suggests UV wavelengths may impede mosquitoes. A study published in the Journal of Medical Entomology in 2015 showed that ultraviolet lights can deter Aedes aegypti mosquitoes, which are vectors for viruses like Zika, dengue, yellow fever, and chikungunya. The researchers shined different colors and types of LED lights on Aedes mosquitoes and counted landing rates. UV LED lights reduced landing by over 50% compared to visible light LEDs.
The researchers believe UV light may overstimulate mosquito eyes adapted to that wavelength. This causes glare or visual “noise” that makes it harder for mosquitoes to spot hosts. Another possibility is that UV alters flight patterns in the mosquitoes. More research is needed to confirm UV light as an effective mosquito deterrent method. But initial results are promising.
| Light Type | Mosquito Landing Rate |
|---|---|
| UV LED | 47% reduction |
| Visible LED | No change |
Other Light Colors Tested Against Mosquitoes
Aside from UV light, other studies have looked at how different colors of visible light affect mosquitoes:
– Red light – One study tested the landing response of Aedes mosquitoes under red, blue, and white light. Mosquitoes landed most often under red light and least often under blue light. Red light may make human skin tones more visible to attract mosquitoes.
– Green light – Mixed results have been found with green light. One study found female Aedes mosquitoes were least attracted to green LED light traps. But another study found no difference in attraction to green light versus white or blue. More research is needed.
– Yellow light – Yellow sodium vapor lamps are sometimes used outdoors as they are energy efficient. But studies show mosquitoes are highly attracted to these yellow-emitting lights. Yellow light strongly attracts night-flying insects.
– Blue/Violet light – Blue and violet wavelengths seem to deter mosquitoes somewhat, though not to the same degree as UV. As mentioned earlier, Aedes mosquitoes had lower landing rates under blue light in lab tests. And traps with blue/violet light caught fewer mosquitoes outdoors than those with white light.
Conclusion
Based on current research, ultraviolet light seems to be the most promising mosquito deterrent, reducing attraction and landing rates in some species like Aedes aegypti. Blue and violet light may also have some deterrent effects. On the other hand, red and yellow light tend to attract mosquitoes. Mosquitoes do not preferentially land on darker colors or avoid lighter ones. Rather, their host-seeking vision relies more on detecting body heat, carbon dioxide, and movement signals. Creating visual distraction with UV light can override some of these cues to discourage mosquitoes from landing. More field studies are needed to confirm if UV and certain light colors can effectively repel mosquitoes in real-world settings. But manipulating light cues offers a chemical-free way to potentially reduce mosquito bites in the future.
