KNOWING how mosquitoes hear could help control the spread diseases like malaria, yellow fever and the Zika virus.

Illnesses carried and transmitted by the insect are responsible for an estimated 725,000 deaths annually and they incapacitate a large proportion of the earth’s population.

Researchers from the University of Brighton have been studying mechanisms by which male mosquitoes use their ‘buzzing’ sound to detect females.

Their findings could lead to the production of acoustic traps, better genetically-modified male mosquitoes and the disruption of mosquito mating, which, in turn, could significantly reduce their numbers.

Mosquitoes are well known for their annoying whine when they fly.

The sound is produced by their wings which beat several hundreds of times per second.

The male’s buzz is typically higher in pitch than that produced by the relatively larger females. Mosquitoes use this frequency difference to detect and communicate with possible mating partners.

The scientists, Dr Patrício Simoes, Phd student Robert Ingham,and Professor Ian Russell, from the university’s neuroscience research group, are working alongside Professor Gabriella Gibson from the University of Greenwich.

They have discovered the male mosquitoes’ hearing organ is actually tuned to the frequency difference between its own flight-tone and a female’s flight-tone.

Central to these findings, was the discovery and description of a stereotypical acoustic behaviour – a specific sound signature – which male mosquitoes produce when they detect female-like sounds.

This never-before described and quantified behaviour is only observed in free-flying males. It enabled the researchers to ‘ask’ male mosquitoes what sounds characteristics are most attractive to males.

Researchers “unexpectedly and surprisingly” found a mismatch between the best tones that evoked the acoustic behaviour and the best tones detected by the hearing organ at the base of the antennae.

This mismatch is solved by the hearing organ by detecting and amplifying the difference between the males’ own flight tone and that of a nearby female.

Dr Simoes said: “Our findings reveal that the remarkable hearing capacities of mosquitoes are based not on harmonic detection, as is generally accepted and described in recent papers and text books, but on the detection of acoustic distortion-products produced by the interaction of the two sounds.

“This discovery gives a new significance for mosquito swarming because it implies that male mosquitoes have to fly in order to acoustically detect, locate and orientate towards flying females.”

Dr Simoes said the full significance of this discover is still being investigated but it holds potential interest for creating new strategies to control mosquito populations, especially for disease-carrying mosquito species.