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I am totally confused whether ask this question to physics or biology stackexchange.
I downloaded a mobile application which claims to repel mosquitoes. This application basically produces sound from 16kHz to 22kHz (I doubt that it even produces more than 20kHz because we can't hear more than 20kHz naturally).
I totally doubt this application. Do mosquitoes go away in higher frequency of sound?
After seeing your question, I decided to do a bit of research on the topic.
"Mosquito repellents that emit high-pitched sounds don't prevent bites"
Some key-points from the webpage:
A Cochrane Systematic Review of the use of electronic mosquito repellents (EMRs) failed to find any evidence that they work.
To test these claims a team of Cochrane Researchers conducted a systematic review looking for trials conducted with EMRs. They located ten field trials that had been carried out in various parts of the world. None of these trials showed any evidence that EMRs work.
All ten studies found that there was no difference in the number of mosquitoes found on the bare body parts of the human participants with or without an EMR
These electronic devices have been shown to have no effect as a mosquito repellent by studies done by the EPA and many universities.
"There was no evidence in the field studies to support any repelling effects of EMRs, hence >no evidence to support their promotion or use" -Ahmadali Enayati, researcher
This is a major point as well:
The study also said that in 12 of the 15 experiments, the landing rates of mosquitoes on subjects was in fact higher than in control groups.
The article also points out that female mosquitoes can't hear very well- Which supports the idea that high-frequency repellents are ineffective; Much more than you probably think. Why? Well, it's pretty simple:
Female Mosquitoes are the only Gender that Bite.
Overall, when you consider the countless studies and research put in to the effects of high-frequency sounds on mosquitoes, it's pretty obvious that:
Ultrasound emitting devices are used to repel mosquitoes. We tested the repelling properties of a commercially available ultrasound device in a domestic setting in Gabon. Devices emitting three different block frequencies ranging from 3 to 11 kHz were tested in a paired, cross-over blinded and placebo controlled trial during eighteen nights in nine pairs of houses. A total of 7485 mosquitoes (10% Anopheles, 62% Culex, 27% Mansonia and 1% Aedes) were caught, 23 per house per night. There was no significant difference in landing rate between the houses with ultrasound device and the houses with placebo for any species of mosquito. Thus the ultrasound device used was not effective against mosquitoes in this strictly controlled trial.
A bibliographic review about the use of electroacoustic devices with a supposed repellent action on the females of different species of hematophagous mosquitoes is presented. 15 direct references and 2 indirect ones are given, in which it is concluded that these devices do not protect those who have them from the stings of mosquitoes. The names of 9 of the tested devices as well as of 16 of the main species of mosquitoes present in the field tests are mentioned. These tests have been carried out in very different ecological conditions from Alaska to Equatorial Africa. It is also stressed that the high intensity ultrasonic frequencies emitted by these devices produces a potentially harmful effect on man.
Rev Cubana Med Trop. 1998;50(2):89-92.
[Electronic repellents against mosquitoes: the propaganda and the reality].
[Article in Spanish]
Coro F(1), Suárez S.
Author information: (1)Facultad de Biología, Universidad de La Habana, Ciudad de La Habana, Cuba.
PMID: 10349423 [PubMed - indexed for MEDLINE]
