In recent years, thousands of electronic mosquito repellers have appeared in online stores. Manufacturers claim their products repel mosquitoes, whereas opinions of Amazon consumers often vary. Some are happy with their purchases, saying the ultrasonic repellers helped them to get rid of mosquitoes, while others lament that it was waste of money and the devices failed to do the job. We have analyzed opinions expressed by scientists and prepared a review of ultrasonic mosquito repellers. What do experiments show? Are there devices capable of eliminating these annoying pests at least for a short period of time? Does ultrasound has a future as an insect electronic repellent? All these issues are covered in our investigative report. For better clarity, we have drawn up a comparative table of types of electronic mosquito repellents. Our review of 10 the most popular Amazon products designed to repel or kill mosquitoes will help you to make the right choice. If you are interested to learn about mosquito biology, how they perceive sounds and in what frequency range, read the last section at the end of the article.
Table of Contents
- Do Ultrasonic Mosquito Repellers Work?
- Electronic Mosquito Repellers: Advantages & Disadvantages: Comparison Table of Their Effectiveness
- TOP-4 Electronic Mosquito Repellents
- What Scientists Say About The Effectiveness of Ultrasonic Mosquito Repellents
There is a number of options of electronic mosquito repellers: ultrasonic mosquito repellers, devices fitted with repellent mats, smartphone apps generating ultrasound and the like. But what about their effectiveness? The thing is that many scientists claim ultrasound mosquito repellers to be useless as a pest control measure. Why? Let’s start with mobile apps. In 2012, BBC cited a renown entomologist Bart Knols as saying that smartphone apps advertised as mosquito repellents actually have no impact on these pests. He conducted an experiment, reaching with such phone into a cage full of mosquitoes. They seemed to ignore the signal and even landed on the hand.
So, what conclusions should we draw? First of all, let's make it clear — this experiment is about mobile apps only and by no means demonstrates the ineffectiveness of ultrasound as a mosquito repellent as a whole. The matter concerns just mobile phones that are not powerful devices and mosquito repelling apps generating a frequency of 15 kHz. As a reference, ultrasound starts from 16-20 kHz, therefore, apps with the indicated frequency can hardly become an illustrative example. At the same time, scientists have revealed that mosquitoes respond to ultrasound in the 35 kHz - 60 kHz frequency range. “It was established that the 35-60 kHz sound of C. afra [a mosquito species] consisted of 5046 calls of FM and CF modulated harmonics. The calls were generated through tongue clicks at the rate of 493.016 calls/minute,” the study says.
Apart from that, let’s face it — the idea of mosquito repelling apps is tempting by itself due to its convenience and simplicity. So, various manufacturers are still rekindling dreams of releasing such product which will be a working one. Just recently, LG has introduced a budget phone with a built-in ultrasonic sound wave technology designed to repel mosquitoes.
Now, what about more powerful devices with a higher frequency? Entomologists from Kansas State University have undertaken a study and concluded that “ultrasound in general is not a promising tool for repelling mosquitoes.” Many commercial mosquito repellers generate constant sound patterns and insects can become accustomed to the noise. For this reason, the University’s scientists have developed their own device producing random sound patterns with the frequency range from 20 kHz to 100 kHz. Some mosquitoes were exposed to ultrasound while other were treated with DEET, a chemical repellent.
“In some experiments resulted in statistically significant differences in the distribution of mosquitoes within a chamber compared to a chamber without ultrasound. However, the magnitude of these differences in mosquito distribution was significantly lower than that with DEET treatment. Therefore, the practical application of ultrasound against mosquitoes was less than convincing,” the report says. According to the entomologists, this is due to the fact that females are less sensitive to sound.
What conclusions can be drawn from this analysis? First of all, scientists have not found this solution effective in mosquito control, but this does not mean that mosquitoes do not perceive ultrasound. This is about the level of impact significant for pest control. Moreover, the scientists compared the results with those from DEET treatment. Although the advantage of chemicals is obvious, the study did not take into account risks posed by chemical repellents to the human health and environment that are actually essential.
During another study, undertaken by Egerton University in Kenya, the female mosquitoes were exposed to 35-60 kHz frequency band of the naturally generated ultrasound of the African bat. As a result, only 40% of the insects remained immobile, in other words, affected by the ultrasound. Researchers have detected a correlation between acoustic waves and amplitude, frequency as well as bandwidth. Acoustic waves influenced the mosquitoes’ activity but there was no significant repelling effect due to the lack of pulsation and a short duration of high-frequency sounds. Despite the fact, that the study has not confirmed ultrasound to be an effective repeller, it looks much more optimistic.
Meanwhile, scientists increasingly consider combining ultrasound mosquito repellers with other technologies with the view of attaining a positive effect. In 2015, scientists from the University of Ibadan conducted a study commissioned by LG Electronics. They used an ultrasonic device in the 20-100 kHz frequency range built in a conditioner circulating cool air. The purpose of the experiment carried out in Nigeria was to repel adult mosquitoes. The experiment was on the basis of switching “ON” and “OFF” of the fan and ultrasonic device. As a result, after a day of exposing mosquitoes to ultrasound, 60.7%, 15.3% and 17.3% of the mosquitoes died during the experiments “fan ON + ultrasonic ON”, “fan ON + ultrasonic OFF”, and “fan OFF + ultrasonic ON” respectively. The proportion of the repelled mosquitoes was 62.7%, 13.3%, 26.0% respectively. The scientists have concluded that a combination of the ultrasonic device and fan both switched on was more effective in killing and repelling mosquitoes. Moreover, the higher a frequency is, the more mosquitoes are knocked down.
Recently, LG Electronics has launched production of air conditioners with built-in speakers making ultrasonic waves at a specific frequency of over 30 kHz. Critics claim that such fans just dry out mosquitoes killing them by means of air circulation. Nevertheless, this does not explain why 17.3% of mosquitoes were knocked down and 26.0% repelled when the fan was off.
Another original solution is a portable device repelling mosquitoes with ultrasound. Actually, much depends on technical features of each specific product. Let’s have a look at SOARING portable ultrasonic mosquito repeller which is small enough to fit in a pocket and, therefore, is a good option for outdoor activities. It has two modes — to repel mosquitoes or dragonflies. When the mosquito mode is on, the device generates a frequency from 22 to 28 kHz. This is a lower threshold, given that generally ultrasound units operate with frequencies from 20 kHz up to several gigahertz. Although the device does generate ultrasound, this frequency is not considered to be effective against mosquitoes. As we have mentioned above, scientists conducted studies and tests using frequencies from 35 kHz and more.
The second question we should ask ourselves is whether portable units are powerful enough to be full-fledged mosquito repellers. Specialists from New Mexico Department of Agriculture claim that portable electronic devices using high-frequency ultrasonic sound are among ineffective pest control options. According to them such products “do not significantly reduce mosquito populations or the incidence of bites.” In other words, experts do not say that portable ultrasonic device does not work at all against mosquitoes. They mean that these products should not be considered as a reliable pest control solution.
A good option is repellent mats releasing various chemicals, like allethrin and metofluthrin, after they are heated by a fuel cartridge or circulated by a battery-powered fan. In other words, the active ingredient is made active by an electronic device. Such units may be compact or have a larger size. The key advantage is that they provide durable protection and do not require applying chemicals to the skin or spraying them. And yet, a chemical substance is released, which is why we cannot state that this solution is absolutely harmless.
In 2016, a reputed website Science Daily published an article about researchers from New Mexico State University who tested the effectiveness of commercially available wearable electronic mosquito repellents. The results have shown that devices with a built-in fan circulating metofluthrin both repel and kill mosquitoes. “Though the study is ongoing, preliminary data revealed that citronella-based bracelets and wristbands have little effect on mosquitoes, whereas OFF Clip-On devices not only repel mosquitoes, they also kill them,” the article reads.
|Smartphone apps||A modern and promising approach. Very convenient and absolutely safe. Some customers claim smartphone apps work against mosquitoes.||Scientific studies show they do not work. These apps generate a frequency of 15 kHz, whereas ultrasound starts from 16-20 kHz.||3|
|Ultrasonic mosquito repellers||Safe, do not require using chemicals. It is considered to be a modern and promising approach.||Scientists claim that the ultrasonic devices do not provide sufficient protection against mosquitoes. If the location and sound pattern of the device are not regularly changed, mosquitoes will habituate to the noise.||4|
|Air conditioner with a built-in ultrasonic devices||The study has shown that a combination of the ultrasonic device and fan, when both switched on, is more effective in killing and repelling mosquitoes. A convenient and safe solution.||It is intended for using indoors only. Critics claim that such fans just dry out mosquitoes killing them by means of air circulation.||9|
|Devices fit with repellent mats||Scientific studies show they are effective both in killing and repelling. You do not have to spray chemicals or apply them on the skin. Provide durable protection||Can be harmful if swallowed or inhaled. For using outdoors only.||10|
Below you will find a review of the four most popular electronic mosquito repellers. First, these are devices fit with repellent mats which release chemicals, such as allethrin and metofluthrin. The chemicals are heated by a fuel cartridge or circulated by a battery-powered fan. Various designs are available, from a military-style portable device to a lantern and clip-on fan. Pick the item you like better. In case you do not want to use chemicals, opt for a compact ultrasound mosquito repeller which covers a larger area and is absolutely non-toxic/
ThermaCELL Outdoor Electronic Mosquito Repellent
Unlike many chemical solutions, this one does not produce any foul smell, nor should the stuff be applied on the skin or clothes. One package includes the device itself, repellent mats and a fuel cartridge. The latter heats a repellent mat that results in releasing allethrin, a botanical insecticide repelling mosquitoes. As the producer pointed out, US Army included Thermacell in the equipment of its soldiers in war zones. The disadvantage is that a holster is not included, which is not convenient and you will probably have to purchase it separately.
Ensuring 12-hour protection for an area of 15 sq ft, the repeller is a good choice for long outdoor activities, like hiking and camping. And not only that. Place the device in the garden or near the porch so that mosquitoes do not disturb you in the evenings. However, since you deal with chemicals, take all necessary precautions to avoid burning or irritation of the skin.
This electronic mosquito repellent has scored 4.1 out of 5 stars in reviews on Amazon. “Add Thermacell to the list of handiest little inventions on Earth. These things do actually work. You will need the butane refills and the replacement repellent mats. A mat will last about 4 hours,” a customer said.
Price: from ~$14. Check the current price
Thermacell MR-9SB Mosquito Repeller plus Lantern
Another product by this company has a similar mode of operation — it heats a repellent mat releasing allethrin that repels mosquitoes covering up to 15 sq ft. The difference is in a lantern with energy-efficient LED bulbs included in the package.The lantern can also be used independently and will come in handy for outdoor activities. Apart from that, the product comes with a 12-hour fuel cartridge and 3 repellent mats lasting up to 4 hours. Compared with the previous product, this one has an advantage of a lower price.
Thermacell Lantern rates 4.1 out of 5 stars on Amazon.com. “Popped this on during my camping trip when there were supposed to be a horde of mosquitoes where I was setting up. Didn't even get one bite,” a buyer noted. He added that the unit gave off is a warm glow and did not attract insects.
Price: ~$15.40. Check the current price
SOARING Portable Ultrasonic Mosquito Repeller
SOARING ultrasonic mosquito repeller which is portable and lightweight — just 1.6 ounce. You can easily put it in the pocket without worrying about having a holster or other accessory. The device has several modes. Choose a frequency between 22 and 28 kHz to target mosquitoes or 35 Hz to repel dragonflies. Apart from that, you may turn on “alarm” and the repeller will produce sounds or switch on LED lights. All these functions are just what a person needs when going hiking or camping.
The mosquito mode operates at an ultrasonic frequency but not as high as scientists use in their studies. According to researchers, frequencies starting from 35 kHz are more effective against mosquitoes. This electronic mosquito repeller covers an area of over 100 sq ft, which is much more than the claimed coverage of the previous products. This is a clear advantage of using sound as a repellent since it reaches longer distances.
The product rates 2.6 out of 5 stars on Amazon.com. However, half of the customer reviews are positive. “I've used this at the lake in the evening, a wooded area at night, and an afternoon backyard bbq. I have yet to get a mosquito bite. I'm that person that always has a ton, regardless of how much spray I use. I'm so impressed!” a user said. Others complain about some technical glitches, such as batteries not making contacts.
Price: ~$18.99. Check the current price
OFF! Clip-on Mosquito Repellent Fan, 2-Pack
The device is supplied with a chemical compound, 31.2% of metofluthrin, a pyrethroid used in pest control. Laboratory and field trials of metofluthrin show that its vapors are capable of deterring over 90% of mosquitoes. And these are vapors of this substance that do the job. How does the device work? Quite simple: a quiet clip-on fan circulates metofluthrin all around the person, protecting him or her from mosquito bites. It runs on batteries that are included in the pack. The product also comes with a single refill while additional ones should be purchased separately. The device provides a 12-hour protection and does not have any smell. According to a reputed science news website Science Daily, this clip-on fan is highly recommended by scientists from New Mexico State University as an effective solution for mosquito control, whether you are having a rest on the lawn or going hiking. Just clip the unit to your belt or waistband, and that’s it!
However, there are some disadvantages. The biggest downside is that you should stand still to make it work. If you move, you should stop, then, allow a few minutes for the device to rebuild its protection. Therefore, it will not work when you are walking without stopping. First of all, there is still a risk that this low-toxic chemical compound can be inhaled or cause the skin irritation.
OFF! electronic mosquito repellent rates 3.4 out of 5 stars on Amazon.com. “My husband purchased the Off Clip-on, & I must say, I did not get bit at all. I went last month to San Juan, Puerto Rico for 4 days. I came home without a single bite. Love my Clip on,” a buyer said. But not all of the customers shared this point of view, some claim the product does not work. “Not one of the three clip-on fans I purchased worked properly. One had corroded batteries,” a disappointed customer wrote.
Price: ~$14.99. Check the current price
Which Other Devices Can Be Used Against Mosquitoes?
As you can see, there are not a lot of electronic mosquito repellers on the market. Now, since we are talking about electronic devices, let us have a look at other units which can be used in mosquito control. These are solutions intended not to repel but kill the pests, as well as chemical and natural repellents that are the most proven and effective measures.
Various options can be considered, including outdoor and indoor devices, as well as those requiring an active human participation or, on the contrary, fully automated ones. Perhaps the most amusing and, at the same time, simple device is an electronic racket with a powerful 3,000-volt grid at a price of ~$16.99. A great alternative to a traditional swatter, a single swing of which will immediately electrocute annoying pests. Turn your efforts to eliminate mosquitoes into an amusement. Be sporty and stay unbitten thanks to Zap-It Racket! Once you have tired of these exercises, switch it a bug zapper mode and the racket will attract mosquitoes with a built-in LED light to electrocute them on contact.
If you need to protect large areas indoors, choose Aspectek 20W Mosquito Killer at a price of ~$32.99. It covers up to 6,000 sq ft of the space and is in demand among owners of public gathering places. The unit is convenient in use, it can be either hanged or just put on any flat surface. It is fitted with UV lamps that are as bright as a 75W lamp, which is crucial as you need to lure as many mosquitoes as possible into the electric grid to get them electrocuted.
Our friend David has recently tried a similar device during his stay in China and remained satisfied with that. As he told us, bug zappers like Aspectek were operating in the hotel’s restaurant and are often placed in small cafes. They really work, killing a variety of biting insects that China has in abundance. David has noted that such zappers may be not effective enough when used in open spaces, however, if there is roofing or a partially covered space, the device will do the job. And yet, if you want to eradicate mosquitoes outdoors, choose a solution specifically designed for this purpose, such as Flowtron electronic device at a price of ~$47.89. It protects a much larger area, approximately half an acre, and is waterproof. It attracts the pests by means of the LED light equal to that of a 100-Watt lamp. Apart from that, Octenol can be used as an additional attractant.
Nevertheless, no matter how enticing the idea of using advanced technologies sounds, for now, the most reliable repellents are chemical ones designed to be applied to the skin or clothes. A range of such products available online is impressing, so let us focus on a few proven chemical repellents. Repel 100 Insect Repellent with an active ingredient DEET which is the most common and reliable chemical compound used against various pests. Its concentration is high, 98.11%, so, be sure to follow all label directions to avoid any potential harm to the health. But the product at a price of ~$7.89 is worth it because Repel 100 provides a durable ten-hour protection under conditions of a heavy mosquito infestation.
While this repellent can be applied to the skin, another sustainable solution, Sawyer Insect Repellent based on permethrin is labeled for treating clothes only. It is a bit more expensive, about $18, but is much more durable, lasting up to six weeks and effective even after several washings. The drawback is in its high toxicity and the smell disappearing only when the treated clothes are dry.
Yes, chemicals are toxic. In case it is so important to you, take another approach and use liquids based on natural ingredients, such as REPEL Lemon Eucalyptus at a price of ~$6.66. It contains oil of Lemon Eucalyptus that safe and environmentally friendly. However, all advantages are always next to disadvantages. In this particular case, the repellent has a short-term effect and requires repeated applications — and it is all because of the natural ingredients.
TOP 10 Mosquito Control Products: Comparative Chart
Thermacell Outdoor Electronic Mosquito Repellent
|Electronic device releasing allethrin.|
Thermacell MR-9SB Mosquito Repeller plus Lantern
|Electronic device releasing allethrin and a LED lamp attracting mosquitoes.|
SOARING Portable Ultrasonic Mosquito Repeller
|Portable ultrasonic mosquito repeller|
OFF! Clip-on Mosquito Repellent Fan, 2-Pack
|Clip-on fan circulating metofluthrin|
|Racket with the electronic grid and LED lights|
Aspectek 20W Mosquito Killer
|Indoor bug zapper for large areas|
|Outdoor bug zapper for large areas|
|Insect repellent, DEET — active ingredient|
|Insect repellent, Permethrin — active ingredient|
REPEL Lemon Eucalyptus
|Insect repellent, Oil of Lemon Eucalyptus — active ingredient|
What should we know about ultrasonic mosquito devices? Ultrasound waves have a frequency range from 16-20 kHz to several gigahertz and are inaudible to humans. Why is that? Human eardrums cannot vibrate at such frequency but many insects are sensitive to ultrasound. Moreover, some animals and insects are capable of producing it. Particularly, this is the case with bats. According to the latest scientific studies, ultrasonic cries produced by bats are effective at repelling night-flying insects. The latter avoid such signals in order not to be eaten. So, why do scientists believe that ultrasound can repel mosquitoes?
“Two theories have been used to explain the repellent action of sound on mosquitoes: first, inseminated females are repelled by the wing beat of males in flight and, second, that mosquitoes avoid the ultrasonic cries of bats,” the study published by the International Research Journal of Engineering Science, Technology and Innovation says. First of all, these are insects preyed upon by bats that can easily detect ultrasonic signals. This capability has been developed primarily in such species as moths and crickets which typically constitute a diet of bats. They have a sort of eardrums on their front legs.
Mosquitoes have a so-called Johnston's organ — a collection of sensory cells in the antennae — that consists of scolopidia, each of which has a mechanosensory chordotonal neuron. This is their auditory system that can discriminate frequencies. Researchers have found that mosquitoes possess “several groups of auditory neurons which are distinct in their frequency tuning, with individual frequencies ranging from 85 to 470 Hz”. However, scientific studies are underway and new capabilities of mosquitoes are being discovered. The thing is that mosquitoes nature has not been fully explored yet. For example, in 2009, Ronald Hoy from Cornell University, New York, has discovered that both the male and female mosquitoes can hear and respond to sounds up to 2 kHz. He has found that mosquitoes produce their signature buzzes by flapping the wings at different speeds per second.
“The A. aegypti mosquitoes changed their wing-flapping so that the male's second harmonic (two times its wing-beat frequency) matched the female's third harmonic. The result was a kind of mating duet of around 1,200 Hz. Other tests of the mosquitoes' "ears," called the Johnston's organ, revealed the whining insects can detect frequencies at least as high as 2,000 Hz,” the paper reads. Although 2 kHz is not in the range of ultrasound, the discovery itself indicates that we still have too little knowledge about these insects.
Some scientists have revealed over the course of their experiments that mosquitoes respond to ultrasound in the range of 38-44 kHz. Ultrasound affects their nervous system so that mosquitoes tend to avoid its signals. However, the repelling or knockdown effect is not significant enough to use ultrasonic devices as a pest control tool, they claim. Many scientists call on to continue studies saying that a complex approach and the use of more powerful devices will enhance the effectiveness of ultrasound mosquito repellers. Also, it is worth considering an approach aimed at attracting the male mosquitoes to ultrasound to control reproduction and a way of their disorientation.
And yet, multiple tests confirm that commercially available products repelling mosquitoes with ultrasound are not capable of significantly lowering populations of these pests. There is still a lot of critics among scientists who believe ultrasound to be completely useless as a pest control measure. Therefore it is obvious that such products as Pest Reject ultrasonic repeller and the like should not be relied on as an effective measure to repel mosquitoes. As Dr. Roger Gold, professor of entomology at Texas A&M University, says, as different species have different kinds of sensors, even those who may respond to sound waves develop “habituation.”
So, what conclusion can we draw? The matter is too contentious and complicated to give a clear answer to the question as to whether ultrasonic mosquito repellers work or do not work. Much depends on the environment, mosquito species, power of the device and other factors. The fact that opinions expressed by customers vary also enforce the argument that it is not that simple. In other words, we should give a try to ultrasound repellers, given the obvious advantages they have.