Mosquitoes can hear from longer distances than previously thought

While most hearing experts would say an eardrum is required for long-distance hearing, a new study from Binghamton University and Cornell University has found that Aedes Aegypti mosquitos can use their antennae to detect sounds that are at least 10 meters away.

Mosquitoes have been known to use a variety of senses to detect the presence of potential mates and food sources. They can see, smell and, most importantly, hear what is around them.

However, it was previously believed that their hearing capabilities were limited. While a vast number of animals hear by detecting tiny sound-induced air motion using fine hairs on their bodies, it has been generally believed that these types of creatures can hear only sounds that originate at distances up to a few inches away.

Professors Ron Hoy and Laura Harrington from Cornell University have been studying mosquito hearing in mating behavior for a while and Hoy encouraged post-doc Gil Menda to start recording nervous activity in the mosquito’s antenna nerve when stimulated by sound.

“The base of the antenna is the hub for 15,000 nerve cells,” explained Menda. “We found some really shocking responses from the antenna nerve.”

After finding that mosquitoes’ nerves were sensitive to sounds at long distances, Hoy and Menda worked with longtime collaborator Distinguished Professor Ron Miles from Binghamton University.

“We put the mosquitoes into my lab, which is an anechoic chamber.,” Miles explained. “It’s designed to absorb sound so that when you’re conducting a study, there’s no background noise or sound reflections interfering with your results.”

With the mosquitoes in the anechoic chamber, the team was able to test their response to various sounds.

“We were able to observe the behavior of male mosquitoes to recorded sounds of either male or female mosquitoes,” said Miles. “When the sounds from male mosquitoes were played, the males mostly just sat there. But when we played the sounds of females, the males took off flying. We were also able to measure the neural response of their antennae and found they can hear sounds from surprisingly far away in the same frequencies that are important for human speech.”

The study was not focused on whether that hearing capability was a driving factor in where mosquitoes find their human hosts, but it has been known that hearing is important for mosquitoes to find mates.

For Miles, this study is another step toward building more powerful, directional microphones. He has looked at the hearing of mosquitos previously for inspiration and has even found ways to incorporate spider silk to perfect microphones.

The study titled, “The Long and Short of Hearing in the Mosquito Aedes aegypti,” was published in Current Biology on Feb. 7, 2019.