Keeping bugs away can be a challenge during the warmer months. Mosquitoes, moths, and other flying insects are attracted to light, which can lead to an infestation if you’re not careful. But not all colours of light attract bugs equally. So what colour light is best for keeping bugs at bay?
How Bugs Use Light
To understand which colours deter bugs, it helps to know a bit about how they use light. Many night-flying insects use light for navigation. They are attracted to brighter areas which they use as guides. Bright lights throw them off course, drawing them in. Once near the light, they become confused and trapped.
Some major culprits that navigate by light:
| Mosquitoes | Moths |
| Midges | Mayflies |
Light also attracts bugs looking for warm-blooded hosts to bite, like mosquitoes seeking a blood meal. Finally, some insects are drawn to light sources that resemble flowers or water, which they mistake for feeding and breeding grounds.
Colours That Repel Bugs
So which colours are least attractive to insects? Studies have compared how different colours of light impact mosquito and moth activity:
Red Light: Red light attracts fewer insects than other colours. This is likely because few flowers or animal eyes reflect red light strongly. So fewer bugs navigate towards it. One study saw 40% fewer moth captures with red light traps compared to white light.
Orange Light: Orange light also appears to attract fewer insects than broader spectrum light. Like red light, few natural objects strongly reflect orange. In the same moth study, orange light reduced captures by about 25% relative to white light.
Yellow Light: Yellow light does not seem to deter insects. It attracts a fair number of pollen- and nectar-seeking insects. Mosquitoes also appear to respond normally to yellow light. It does not offer much advantage over white light for repelling bugs.
Green Light: Green light seems to attract a lot of winged insects. Many bugs target the green-yellow wavelengths reflected by leaves and foliage. One study even found more mosquito landings under green light than white, likely because it mimics natural plant reflections.
Blue Light: Interestingly, blue light can reduce mosquito activity. In the same mosquito study, blue light resulted in the fewest landings. Shorter blue wavelengths may resemble natural water reflections less than other colours. One downside is that blue light may make it harder for humans to see certain flying insects.
Ultraviolet (UV) Light: UV wavelengths seem to attract many flying insects. Light traps for monitoring bug populations often use UV light alongside visible wavelengths. Mosquitoes, midges, and many other insects respond strongly to UV. Natural sources like flowers and animal fur reflect UV, drawing insects in. It is best avoided for deterring bugs.
The Verdict
Based on the evidence, shorter wavelength light in the red to blue region seems best for deterring many flying insects. Here is a summary of the research on how different colours impact attraction:
| Colour | Impact on Attraction |
|---|---|
| Red | Strongly reduces attraction |
| Orange | Moderately reduces attraction |
| Yellow | No major impact on attraction |
| Green | Increases attraction |
| Blue | Moderately reduces attraction |
| Ultraviolet | Strongly increases attraction |
The shortest wavelengths, from deep red to blue, seem to confuse insects the most. Reflections in this range don’t resemble their natural navigation targets as much.
Based on these findings, deep red light is likely the best for repelling mosquitoes, moths, and other flying bugs. Red has repeatedly performed well at lowering insect attraction across studies.
Orange light also reduced attraction, though perhaps not as strongly as red. Blue light seems promising for deterring mosquitoes, but may make spotting some insects harder. Greens, yellows, and UV wavelengths are best avoided.
Putting Red Light to Use
Here are some ways to leverage red light’s powers against bugs:
Outdoor Lighting
Use red bulbs in outdoor fixtures around patios, decks, or doorways. This can make these spaces less inviting to pests. Go for deep reds rather than pinkish hues for best results.
Bug Zappers
Many electrocuting bug zappers use UV light to attract insects. Swapping these bulbs for red ones can reduce the number lured in.
Flood Lights
Red flood lights pointed away from outdoor gathering spaces can divert bugs away through repellent effects. Place them around the perimeter of yards or patios.
Camping & Patios
Portable red camping lights are available. These can provide visibility for humans while minimizing unwanted pest attention.
Nighttime Events
Red lighting used for outdoor concerts, festivals, or movie screenings may help make events more comfortable by repelling airborne pests.
Red Pest Control Bulbs
Specialty bulbs combine red wavelengths with other colours known to repel insects. These can provide customizable outdoor lighting solutions.
Complementary Tactics
While red light can help divert flying insects, additional strategies should be used alongside it:
Eliminate Standing Water
This removes mosquito breeding sites. Drain sources like clogged gutters, flower pots, birdbaths, old tires, and buckets. Mosquito Dunks can also be applied to water sources that cannot be drained.
Use Fans
Fans make it harder for mosquitoes and other weak fliers to navigate towards humans. Position floor or tower fans on patios or outdoor gathering spaces.
Remove Flowering Plants
Get rid of flowering plants, bushes, and trees around the home, especially fragrant ones. These attract pollen-seeking insects like moths. Replace them with non-flowering plants.
Apply Insect Repellent
Topical repellents on exposed skin add another layer of protection against biting. Use EPA-approved products like those containing DEET or picaridin.
Deploy Residual Sprays
Longer-lasting sprays around yards can further deter mosquito activity. Products with permethrin or bifenthrin provide outdoor residual effects.
Use Protective Clothing
Wear long pants and sleeves outdoors to minimize exposed skin. Light colours are also less attractive to some insects.
Potential Downsides of Red Light
While research indicates red light can help divert bugs, a few downsides should be considered:
Light Pollution
Excess outdoor red lighting contributes to light pollution, which can disrupt ecosystems and circadian rhythms. Use red bulbs sparingly and shield fixtures to minimize glare.
Reduced Visibility
Red light provides lower visibility for humans compared to white light. Dim red lights in high traffic areas could potentially impact safety. Keep additional white lighting for visibility where needed.
Higher Energy Usage
Red light bulbs tend to consume more energy to product the same brightness as typical bulbs. Use energy efficient LED red bulbs to help offset this.
Mixed Research
While research indicates red light attracts fewer bugs than white light, studies are limited. Impact can vary by species and habitat. Red light may perform differently in certain conditions.
Not 100% Effective
Red light does not fully eliminate attraction, just reduces it. Flying insects can still be drawn in. Relying solely on red light is not enough for serious infestations.
Conclusion
Flying insect pests can quickly ruin outdoor enjoyment. Manifold studies suggest red light attracts the fewest mosquitoes, moths, and other bugs compared to other colors. Red likely interferes with their navigation systems most. Slowing attraction can provide a useful additional deterrent alongside other tactics like drainage, fans, and repellents.
However, red light should be used judiciously. Excess use contributes to pollution and inefficiency. And it cannot substitute for eliminating breeding grounds or total exclusion when needed. But as part of an integrated pest management plan, the strategic use of red light can provide a handy extra boost against invading airborne insects. Carefully deployed, it can help reclaim outdoor living spaces from nature’s pests.
