Are Mosquitoes Attracted to Light?

Mosquitoes are vectors of many diseases, and to prevent these diseases, there is often not much of an alternative to chemical treatments for mosquito eradication. But this can be detrimental to the environment and cause resistance in the mosquitoes.

So alternative ways of reducing mosquito populations are needed. Bug zappers that use fluorescent tubes to produce UV light aren’t very effective at killing mosquitoes, although they kill many other insects.

Are there certain color lights or different bulbs that could attract mosquitoes? Or are there lights that could be used in houses that would be less attractive to mosquitoes?

What Attracts Mosquitoes?

Female mosquitoes need a blood meal to produce their eggs. So they need to find a host, human or animal. They use different senses to achieve this. Most importantly, mosquitoes will smell the carbon dioxide exhaled in our breath. Then as they approach, they pick up our body heat and other odors like sweat.

They don’t need light to find us. In fact, one of the most annoying things about these pesky insects is their incessant buzzing around our heads in the night.

Does Light Attract Mosquitoes?

The answer to this question isn’t a straightforward yes or no. Night-biting mosquitoes avoid sunlight by resting in a shady place during the day. So it could be said they don’t like bright light.

But different species are attracted to different types of light at different times of the day. Additionally, mosquito sex can make a difference.

In a study by the University of California, they found that day or night-biting mosquitoes can be attracted or repelled by certain colors of light at different times of the day.

The same study shows that day-biting mosquitoes, especially females searching for a blood meal, are attracted to any color of light during the day. On the other hand, night-biting mosquitoes avoided ultraviolet and blue light during the day.

What Type of Light Attracts Mosquitoes?

Again different studies show the certain species of mosquitoes are attracted by certain types of light.

The University of Florida tested mosquito traps using Ultraviolet LEDs, blacklight bulbs, and incandescent bulbs.

With the night-biting mosquitoes of the Anopheles quadrimaculatus and Culex quinquefasciatus species, the overall capture rate was less than 15%.

The capture rate for the day-biting Aedes aegypti was much greater, with the UV LED having the most success with little difference between the blacklight bulbs and the incandescent bulbs.

Although the attractiveness of lights is dependent on species, they all seem to be attracted to light to some extent.

Why Are Mosquitoes Attracted to Light Sources?

There are a few theories on this subject, so we’ll consider them all, and you can draw your own conclusions.

Many insects, such as moths, flies, and mosquitoes, are attracted to light sources. The insects’ response to light is known as phototaxis, which is the ability to move towards or away from a light source.

Moths or mosquitoes have positive phototaxis, which means they move towards light. Cockroaches or silverfish have negative phototaxis: they flee light. Entomologists aren’t sure why many insects have a positive phototaxis, but here are some theories.

The first theory is that insects use natural light sources such as the moon or stars for navigation. They keep themselves aligned at a certain angle to the natural light source. As the moon is far away, the angle stays the same. Artificial lights interfere with navigation and disorientate the insects.

Another theory is that insects see a light source as a direct path and fly towards it, knowing there are no obstructions. Some insects don’t stop, collide with the light, and can be injured or killed.

The last theory suggests that as flowers reflect UV light, some insects may be attracted to artificial lights that emit UV. Mistaking them for flowers.

What Color Light Are Mosquitoes Attracted To?

One study using CDC light traps shows that green LEDs are the most attractive color for catching mosquitoes, followed by blue.

Another study using blue, green, red, and infrared LED-equipped sticky cards had similar results catching nearly 44% of 15 species of mosquitoes with a green LED. The blue LED also performed well.

How Effective Are UV Light Devices In Attracting and Trapping Mosquitoes?

Many bug zappers and some traps use UV light to attract insects. These devices are very efficient at attracting flying insects like moths or beetles but less effective at capturing or killing biting insects.

blue glow of UV bug zapper

Bug zappers do kill a minimal number of mosquitoes. In research using bug zappers, mentioned by the American Mosquito Association, “mosquitoes comprised merely 4.1% and 6.4% respectively of the daily catch over an entire season”.

The problem with these devices that use UV light as an attractant is that they kill large numbers of beneficial insects. This, in turn, can affect other animals such as birds and bats, which eat large numbers of insects, including mosquitoes.

Some entomologists even suggest the ultraviolet light used in bug zappers may attract mosquitoes near you. Once in your vicinity, they will find your exhaled carbon dioxide more interesting than the light they initially came to explore. They may profit from hanging around and biting you!

Many studies suggest these UV electrocuting devices should be avoided. Traps that use ultraviolet light usually use CO2 as an attractant, so they should catch more mosquitoes.

Does Switching the Lights Off Help to Avoid Mosquitoes?

Having seen some of the studies above, although not many night-biting mosquitoes are attracted by lights, there are still a few.

If you have your doors or windows open, a mosquito will be attracted by the carbon dioxide you exhale more than by the lights in your house. So turning off your lights when the doors are open won’t really make much difference.

What is the Best Light to Use to Get Rid of Mosquitoes?

Lights won’t repel mosquitoes, but some lights may attract fewer mosquitoes than others. The development of domestic lights that attract fewer mosquitoes could help reduce disease transmission.

A minimally attractive light source or “bug light” would be a dim, red, or yellow LED. Warm colors attract fewer insects. Cool colors like blue, green, or white attract more bugs.

Conclusion

It seems that most mosquitoes are attracted to light to some degree, although the level of attraction is dependent on many variables such as species, sex, type of light bulb, and light color.

The research into the attractiveness of different lights to mosquitoes can be useful for using in more effective traps or producing domestic light bulbs that attract fewer insects.

Scientists at the University of Notre Dame have shown that the Anopheles gambiae mosquito, the major vector of malaria in Africa, refrains from biting after exposure to a pulse of white light. This could be used as a control method in addition to current methods.

Many insect killers using UV light aren’t very effective against mosquitoes but kill large numbers of inoffensive insects. Most mosquitoes you see at night are searching for a blood meal and don’t use light to find you but use CO2, heat, moisture, and body odor.

Don’t rely on bug zappers or even mosquito traps to protect you. They may help but won’t kill all mosquitoes. The best way to protect yourself when outside is to cover up with a long-sleeved shirt, trousers, and an insect repellent such as DEET or Picaridin on any bare skin.

If mosquitoes are a problem when you’re in bed, a mosquito net could be your best solution to avoid bites and give you a good night’s sleep without the annoying whine in your ears.