New device emits female mosquitoes' sounds to trap males

Scientists have developed an effective low-cost device that emits the sound of female mosquitoes in order to trap male Aedes aegypti mosquitoes - the species that carries dengue and yellow fever.
Brian Johnson and Scott Ritchie from James Cook University in Australia set out to make a cheap and effective audio lure for scientists collecting male mosquitoes.
They found a tone of precisely 484 Hertz, the frequency of a female Aedes aegypti's wings, brought 95 per cent of male mosquitoes to the trap.
Johnson said the device cost around USD 20 and could be run by itself for weeks.
"We started with a cheap mobile phone and moved to an even cheaper MP3 player. There are no harmonics, it's a pure tone and very simple to produce," he said.

The effectiveness of the audio lure is easy to see - when it's switched on, mosquitoes flock to the device, and fly away as soon as it's turned off, researchers said.

Male mosquitoes do not bite, but new anti-mosquito strategies involve capturing and sterilising them before releasing them to breed unsuccessfully with females.
"There are a number of projects underway. They required capturing and releasing tens of thousands of male mosquitoes, but most traps are aimed at capturing females," said Johnson.
He said there was no chance of eliminating mosquito populations by trapping males alone, as only a few needed to survive to continue the breeding cycle.

The scientists also found that female mosquitoes were completely oblivious to the sound of male wing beats.
"There's no real need for females to respond to male overtures," said Johnson.
The team is now optimising the trap for field use and coordinating with trap manufacturers to add the feature to their products.