IT’S A BUG’S LIFE A new study, conducted by researchers atCornellandBinghamtonUniversity now finds that mosquitoes can hear over distances much greater than anyone suspected. Their findings were published in the journal Current Biology. Scientistsearlierbelievedthatorganismsrequire eardrumsforlong-rangehearing,andthatthefeathery antennae with fine hairs that mosquitoes and some insects use to hear only worked at close distances of several centimetres (a few inches).However, a serie of experiments has now provided neurophysiologicalandbehavioural evidence that the Aedes aegypti mosquitoes - which transmit such diseases as yellow fever, Dengue, Zika, West Nile and Chikungunya viruses - can hearspecific frequencies asfar away as 10 meters (32 feet) or more.
These frequencies overlapped well with the frequencies of female mosquitoes in flight as well as human speech. Speakingaboutthedevelopment,seniorauthor Ron Hoy, said, “It’s been known for quite a long time that male mosquito e s a r e d r a w n to the soundof the female’s beating wings. Hoy noted that since mos qui toes mateinmid-air,the sound of the female’s wings buzzing sets the males in motion.
Menda fitted mosquitoeswith an electrode in their brains and made neurophysiological recordings of the auditory nerve being stimulated by pure-tones emitted from a loudspeaker 10 meters away. Researchers found that the sweet spot of frequency that the mosquitoes are sensitive to was between 150 to 500 hertz. The mosquitoes’ frequency range for hearing also overlapped with human speech. “The most energetic frequencies of an average human vowel are in the range of 150 to 900 hertz,” Hoy said, so “they should be able to hear” people speaking. While the study offers both neurophysiological and behavioral evidencethatmalemosquitoeshear soundsfrom far field, it offers no proof that they use it to home in on people.The insects are known to pick up sensory cues such as carbon dioxide, odors and warmth to locate people. But the results do show an intriguing correlation, Hoy said.