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Consumers Association magazine "Holiday Which?" denounced some tropical mosquito repellents

Electronic buzzers designed to ward off mosquitoes are a waste of money, a consumer watchdog warned.

Holiday Which? said that tests revealed the devices, which are supposed to frighten off insects by emitting high frequency sounds, did not work against mosquitoes that bite humans. The organisation accused manufacturers of making misleading claims which could endanger lives by giving holidaymakers a false sense of security. It called for the buzzers to be removed from sale and has passed its test results to trading standards officers.

Every year 20,000 Britons catch the life-threatening disease malaria from mosquito bites. Which? tested 18 types of repellent with the London School of Hygiene and Tropical Medicine. It put an expert in a sealed room containing the type of mosquito that spreads malaria. Holiday Which? said four buzzer devices — Lentek MosquitoContro, Master-plug Portable Insect Repeller, Moziban and Prince Lionheart Mosquito Repeller — did not work at all.

Its report said the Prince Lion-heart repeller caused particular concern as it is aimed at protecting infants. As well as claiming to keep mosquitoes outside a five-metre radius, the device also claims to help protect against West Nile Virus, which is transmitted by a different species and can be deadly. But when it was tested by the watchdog it proved useless against both types, said Holiday Which?.

The report said there is no substitute for a skin-applied repellent containing at least 30 per cent of the chemical Deet (N,N-Diethyl-meta-toluamide). Tests showed other types of repellent also performed well. Masta and Lifesystems Expedition 100 wrist and ankle cotton bands, which are soaked in a Deet solution, gave good protection. And coils made of sawdust and insecticide (Boots Repel, Lifesystems and Moskil) to be burned outside performed well in the lab, though the report says they are likely to be less effective outdoors.

Plug-in vaporising devices, which use electricity to release insecticide vapours as you sleep, also did well. All four plug-in brands tested - Boots Repel, Jungle Formula, Lifesystems and Mosqui-Go-Duo - gave 100 per cent protection, killing every mosquito in five minutes. The room spray tested, called Go Bug Wars, also did well, but the report said it is only totally effective if the room is sealed.

Holiday Which? editor Lorna Cowan said: ‘Some repellents offered complete protection and zapped mozzies in next to no time. We think others, such as the buzzers we tried, were a shocking waste of money, didn’t offer any protection at all and offer nothing but a false sense of security. They should be removed from sale.’

A Prince Lionheart spokesman said the ‘avoidance technology’ used in the Electronic Mosquito Repeller was solid. He said: ‘Prince Lionheart does not claim 100 per cent efficacy for our product — and neither do the makers of lotions and sprays — we simply point out that the product provides a safe, skin-friendly, alternative to lotions and sprays. He added the Which? report used mosquitoes that were starved for a number of days and then put to test in a lab. ‘We have found it to be successful in more realistic situations', he said.

based on an article in the Daily Mail Tuesday 6th September, 2005, page 27

Buzzers don't work - update, April 2007

EMRs (Electronic mosquito repellents) are battery-powered hand-held devices that give out a high frequency buzzing sound almost beyond the human hearing range It is claimed that they repel female mosquitoes up to 2½ metres away, either by sounding like male mosquitoes or like bats. (It is the female mosquitoes that bite humans.)

A review of ten field trials in various parts of the world have provided no evidence that the devices were effective. Researchers led by Dr Ahmadali Enayati from the Mazandaran University of Medical Sciences in Iran analysed data from the 10 trials. "All 10 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", said Dr Enayati. "EMRs have no effect on preventing mosquito bites. Therefore there is no justification for marketing them to prevent malaria infection", he said.

The paper was published by the Cochrane Library, part of the Cochrane Collaboration, a UK-registered charity which specialises in research reviews, on 18th April 2007, and can be read in full here.

See also:

An Anopheles stephensi mosquito is obtaining a blood meal from a human host through its pointed proboscis
*Anopheles stephensi mosquito consuming human blood

How the devices compare



Dry Mosi-Bands


Go Bug Guards


Lifesystems Expedition 100







Go Bug Wars





Lentek MosquitoContro


Masterplug Portable Insect Repeller




Prince Lionheart Mosquito Repeller





Boots Repel (liquid)


Jungle Formula (liquid)


Lifesystems (tablets)


Mosqui-Go Duo (liquid/tablets)





Boots Repel









Dry Non-Toxic Mosi-Band


Lentek Bite Shield


Source: Holiday Which?
*Image source: The mosquito image is a work of the Centers for Disease Control and Prevention, part of the United States Department of Health and Human Services, taken or made during the course of an employee's official duties. As a work of the U.S. federal government, the image is in the public domain. Taken from http://commons.wikimedia.org/wiki/File:Anopheles_stephensi.jpeg

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