Is there a light that keeps mosquitoes away?

Mosquitoes can be a nuisance for many people, especially in the warmer months. Their bites can be itchy and irritating, and some mosquitoes can transmit diseases like malaria, Zika, dengue fever, and West Nile virus. This makes finding ways to avoid mosquito bites a priority for a lot of people. Many have wondered whether lights that claim to repel mosquitoes really work or not. There are many products on the market that advertise using light to keep mosquitoes at bay, but do any of them really do the job?

How Mosquitoes Use Light for Navigation

To understand whether lights can deter mosquitoes, it helps to know a bit about how the insects use light. Mosquitoes are attracted to sources of carbon dioxide, warmth, sweat, and other chemical cues that help them locate people and animals to bite. However, they also use visual cues to pinpoint targets. During the day, mosquitoes are attracted to dark colors and shaded areas. At night, they navigate by the moon and artificial lights.

Female mosquitoes, which do the biting, are especially drawn to incandescent bulbs. These lights give off more infrared radiation than LED or fluorescent bulbs, and the heat signatures given off by the bulbs help mosquitoes locate hosts. Mosquitoes are also drawn to light sources that contrast strongly with the surrounding darkness. Any light source that helps a mosquito discern objects and potential hosts in low light conditions will attract them.

Do Bug Zapper Lights Repel Mosquitoes?

One common type of mosquito light trap is the bug zapper. These devices consist of a light source surrounded by an electrified grid. Mosquitoes and other insects are drawn in by the light and then zapped by the grid, killing them. Bug zappers do succeed in killing some mosquitoes that come close enough to be electrocuted. However, they do not effectively repel mosquitoes from an area.

Here are some reasons bug zappers do not work well as repellents:

• The light attracts mosquitoes towards the device, rather than repelling them away.
• Mosquitoes can sense the trap from a distance and avoid contact with the grid.
• The devices only kill insects that pass directly through the electrocution grid.
• Bug zappers do not reduce overall mosquito populations enough to have a meaningful repellent effect.

While bug zappers may kill a few mosquitoes, the light source attracts many more than it kills. It does not create a “mosquito-free zone” around itself. Any mosquito repellent effect is very minimal.

Do UV Mosquito Lights Work?

Another type of mosquito light claims to use ultraviolet (UV) light to repel the pests. UV wavelengths are invisible to humans but visible to insects like mosquitoes. The theory is that mosquitoes will avoid places where UV light is present.

There is some evidence that UV light can deter mosquitoes, but the effect is often limited:

• Low-intensity UV lights may have little effect at keeping mosquitoes at bay.
• The light has to cover a wide area to successfully repel mosquitoes.
• Mosquitoes quickly become habituated if exposed to the same UV system over time.
• UV lights can attract other undesirable insects even as they deter mosquitoes.

Powerful UV systems may provide partial mosquito protection for a given area like a patio or backyard. But most consumer-grade UV bug lights are not strong enough to work very well. The light has to be intense enough and cover a large enough area to properly repel mosquitoes.

Do Electronic Mosquito Repellent Devices Work?

Some mosquito repellent devices claim to use sound, ultrasonic frequencies, or electromagnetic fields to drive mosquitoes away. These types of electronic repellents include:

• Sonic mosquito repellents – Emit high-frequency sounds designed to annoy mosquitoes.
• Ultrasonic repellents – Emit ultrasounds above human hearing range.
• Electromagnetic or electronic repellents – Emit electromagnetic fields that supposedly interfere with mosquito senses.

Unfortunately, there is very little scientific evidence showing these devices effectively repel mosquitoes in real-world conditions:

• Mosquitoes quickly become used to sounds and electromagnetic fields if continuously exposed.
• Claimed ultrasound frequencies are above mosquito hearing ranges.
• Electromagnetic waves have not been shown to disrupt mosquito behavior.
• Effectiveness decreases quickly with distance from the device.

While a few early lab studies indicated some promise, most rigorous testing has found ultrasonic and electromagnetic mosquito repellents do not live up to marketing claims. Consumer Reports, the EPA, and other agencies do not recommend these devices.

Chemical Mosquito Repellents

The most proven type of mosquito repellent comes in the form of topical creams, sprays, oils, and bracelets infused with chemical repellents. Repellents containing the following active ingredients have been approved by health agencies for their ability to repel mosquitoes:

• DEET
• Picaridin
• IR3535
• Oil of lemon eucalyptus
• Para-menthane-diol
• 2-undecanone

These repellents work by masking human chemical cues like carbon dioxide, sweat, and body temperature that attract mosquitoes. They can be applied directly to the skin or clothing and provide protection for a period of hours.

DEET-based repellents tend to provide the longest-lasting protection, often up to 10 hours with a single application. Picaridin and oil of lemon eucalyptus also have long-lasting effects. The CDC recommends using EPA-approved repellents for the most reliable protection against mosquitoes.

Do Citronella Candles or Plants Repel Mosquitoes?

Citronella is a common natural oil promoted as a mosquito repellent. Citronella candles and essential oils are popular mosquito-fighting products. The strong citronella scent is unpleasant to mosquitoes but pleasant to humans. However, citronella has limited effectiveness:

• The aroma dissipates quickly and must be reapplied frequently.
• Citronella mainly repels mosquitoes within a small 2-3 feet radius.
• Any breeze quickly blows the scent away.
• Citronella plants provide little repellent coverage beyond their foliage.

The EPA does not consider citronella a registered or reliable repellent. While citronella candles and plants can provide a small zone of protection, they are not adequate solutions on their own. Stronger repellents like DEET or picaridin work much better.

Mosquito Repellent Clothing and Gear

Specialized mosquito repellent clothing and gear provides long-lasting protection without needing to constantly reapply spray repellents. These products contain embedded repellents that resist multiple washings. Some examples include:

• Repellent wristbands
• Skin patches
• Treated shirts, pants, socks
• Insect repellent gear sprays
• Mosquito net hats
• Repellent patio lanterns

Repellent wearables like treated wristbands can provide convenience, as can wider-area solutions like clip-on repellent diffusers. Mosquito nets hats provide a physical barrier against bites for the head and neck. Long shirts, pants, and socks minimize exposed skin that needs to be covered in repellent.

Are There Any High-Tech Mosquito Repellents?

Some newer high-tech devices and methods also show promise for mosquito control:

• CO2 traps – Lure mosquitoes in using carbon dioxide, then trap or kill them.
• Spatial repellents – Release repellent chemicals across a wide area.
• Attract-and-kill traps – Draw in mosquitoes then kill them with insecticides or adhesive traps.
• Genetic control – Release genetically modified sterile male mosquitoes to suppress populations.
• Repellent dispensers – Automatically release repellent chemicals on a schedule.

While still relatively new, spatial repellents and CO2 traps have shown high effectiveness in tests. Genetic population control methods are also becoming viable. Smart traps that lure mosquitoes in and either trap them or use targeted insecticides also show promise, without needing widespread spraying.

Conclusion

Although many devices and gadgets claim to repel mosquitoes using light, sound, or other methods, most lack strong scientific evidence of effectiveness. Chemical repellents, protective clothing, and some newer technologies have better proven means of deterring mosquitoes. Top EPA-approved repellents, like those containing DEET or picaridin, remain the gold standard for individual protection. Spatial repellents, modern traps, and genetic population control methods also have potential for large-area mosquito control.