Mosquitoes respond to color in surprising ways. Recent lab work shows these insects can be steered by the colors they see after sensing the carbon dioxide we exhale. In practical terms, wearing certain hues could influence where mosquitoes focus their attention, while avoiding others might cut down bites. The findings shed new light on how mosquitoes locate a host and how to design more effective prevention tools.
Researchers at the University of Washington show that a common mosquito species is drawn to specific colors such as red, orange, black, and blue once CO2 from human breath is detected. In contrast, colors like green, purple, blue, and white did not trigger the same approach in the mosquitoes studied. This color preference seems linked to how mosquitoes interpret signals from skin warmth and color cues together, guiding them toward potential hosts.
Experts say the insects rely on a mix of chemical cues and visual signals to find people. Lead author Jeffrey Riffell, a biology professor, notes that mosquitoes appear to use scent to help their eyes pick out nearby targets that could offer a blood meal. When CO2 and other odors are present, the visual system seems tuned to colors that signal a host nearby.
Mosquitoes can transmit disease
When CO2 or other breath-related compounds are detected, the resulting odor seems to trigger the mosquitoes’ visual system, making certain colors more attractive and guiding them toward a potential host. This interaction between smell and sight helps explain why some colors seem more compelling to hungry mosquitoes than others.
The new study, published in Nature Communications, explains how the sense of smell interacts with visual perception to shape host-seeking behavior. By understanding which colors attract or repel mosquitoes, researchers can better tailor repellents, traps, and other control strategies to reduce bites and disease risk.
Skin Color and Mosquito Preference
A common question is what people can do to minimize bites. The researchers identified three well-known signals that attract mosquitoes—breath, sweat, and skin warmth—and added a fourth: red coloration found in clothing and skin. They propose that red hues act as a strong attractant for the target species, regardless of a person’s skin tone. Filtering out red tones or choosing clothing that avoids these colors can help lower bite risk in some settings.
In experiments with female Aedes aegypti mosquitoes, which are known vectors for dengue, yellow fever, chikungunya, and Zika, researchers observed how visual and olfactory cues guide biting behavior. Mosquitoes were exposed to varied colored dots and scents to see how they respond to different cues. The results reaffirm that female mosquitoes seek blood meals and that color, in combination with scent, plays a significant role in host location.
During trials, individuals sprayed with certain odors while presenting different visual patterns showed that color cues could dominate under specific conditions. For instance, red, orange, black, or cyan dots drew more attention than green, blue, or purple dots when CO2 was present. The color preferences aligned with the wavelengths corresponding to longer red-orange tones, which may mirror signals emitted by human skin.
Further work explored how mosquitoes respond when long-wavelength cues are filtered or when a color is replaced with a green glove. The absence of those long-wavelength signals reduced the insects’ responsiveness, underscoring the importance of color in host-seeking behavior. Genetic factors also appeared to influence color preference; certain mutations in scent or vision genes reduced or altered these preferences, highlighting the heritable nature of the trait.
These findings offer actionable clues for mosquito control. By leveraging color signals in the design of traps, screens, and repellents, health programs can improve intervention effectiveness while reducing bite risk for communities in Canada, the United States, and beyond. The study notes that more work is needed to fully map how other cues—such as skin secretions and microclimate around the skin—combine with color to drive approaching behavior in various mosquito species.
The researchers note that different species may show distinct color preferences depending on the host they typically seek. Still, the new evidence provides a foundation for developing non-biomedical strategies to curb bites and disease transmission through color-conscious design in public health tools.
Reference work: Nature Communications