The Sounds of Love

Gabrielle Waldvogel
April 23, 2010

“I have never seen a student so interested in bugs!” said Entomologist Ronald Hoy through a stream of light laughter as he watches his graduate student Lauren Cator’s face only inches from the netted barrier. “Quick! Quick! Look, did you see that?!” exclaims Cator. Her freckled face bends in a wide grin as she gazes wide-eyed at the swarm of mosquitoes collecting at the palm of her outstretched hand. The cloud of tiny specks shoot and zigzag for a moment in a wheel of perfect chaos before dispersing in various directions inside the white, meshy net in which they are kept. “Six seconds is all it takes for them to mate, and then they are done. They just mated in my hand” Cator adds quietly, her blue eyes sparkle, still fixated on the black humming dots. She watches them carefully for a few moments longer with the same concentration a child gives to her birthday candles.
Cator, a graduate student at Cornell University is noted as being the first to discover the unique mating patterns of mosquitoes. The pestering parasitic bugs that buzz relentlessly in our ears are actually quite the singers that attract mates through sweet serenades. Cator has been studying the behavior and anatomy of mosquitoes since 2005, beginning with a 6-month stay in Tanzania. In Tanzania, she worked on a project with Tsetse flies, which are vectors for Malaria. “I realized that studying the behavior of these insects that transmit these diseases is a really good way to try to cut down on the transmission.” Upon her return to Cornell, she began working with mosquitoes. It was not until 2008 that Cator discovered the musical talents of these insects.
Her curiosity was sparked when she read a paper written by a research group at Sussex University. The paper described the behavior of non-swarming mosquitoes in which they showed a pattern of matching with mates depending on complementing flight-tone frequency on a fundamental level. “I read that paper and I thought it was really interesting, but I thought there was no way that my mosquitoes did that. And so it started out as just trying to see if that was happening in my mosquitoes—and it was!” Cator said with a smile. “ But the difference was it was happening with harmonic frequencies.” The mosquitoes studied in the Cornell labs, Aedes aegypti, mate when the frequencies of the male tone and the female tone blend in a perfect (or near perfect) harmony. According to Hoy, the males and females that synchronize at harmonics are better at getting mates. “We have also seen that the off spring of these pairs are more competitive when looking for mates.” Said Hoy. “It is like natural selection on a micro level. The females have highly sensitive ears to detect the frequency of the wings flapping of the male, and then they fly towards them and mate.” Explained Hoy.
“We’ve been studying mosquitoes for a really long time, but we’ve mostly been studying how to kill them,” said Cator. “We never knew how they mate, how they disperse, where they like to hang out, things like their lives!” Cator added enthusiastically with a grin. Cator, and the lab she belongs to, is credited as being the first to discover such details about mosquitoes such as the organized mate selection through matching tone frequencies, and the exceptional hearing qualities of the female mosquitoes. “Finding out about their lives can in the long run really help us prevent or even stop the transmission of Malaria.” Said Cator conclusively.
The way the researchers at Cornell have been studying the neurological responses of mosquitoes is through use of electrodes. Ben Arthur, professor of neurobiology and behavior, and research associate has been working on mosquitoes for the past two years. Unlike Cator, who was interested in the mosquitoes’ unique traits because of the potential effects it can have on the spread and transmission of diseases, Arthur is more interested in the simplicity that is pure science. “ I am a basic scientist, I just like to see how things work. It’s great working with mosquitoes because the field is wide open, not a lot is known. Just over the past few years have people started to look into that, and it’s kind of cool to have been there from the beginning.” Said Arthur, leaning easily back in his chair. “We have been looking at mosquitoes since the 1855 when a man named Johnston said, ‘hey,’ I think those little things (antennae) are ears!” exclaimed Arthur, putting his hands above his head.
Ronald Hoy, Arthur’s co-researcher in the lab explained that through the principles of physiology they have been able to detect the neurological patterns in when mosquitoes are exposed to sound. “We just stick an electrode in there and record the action potentials being sent to the brain.” Said Hoy.
What Arthur and Hoy’s research has shown is that mosquitoes have a very unique ear. In fact, the mechanism that is the mosquito ear is so intricate that their lab has been working to create new microphone technology in collaboration with Binghamton researchers. Ron Miles of Binghamton University explained, “What we do here is try to copy the features of insect ears and develop new ways to improve hearing aids.” According to Miles, there are already a number of microphones that have been made out of silicon.
Cator is enthusiastic about the future research to be done, and plans on returning to Tanzania for a third time. “As of now we have seen that females have this acute ear, but I want to know why. They are matching at these frequencies, but why? What does that mean?” Cator give a small shrug. “There is so much left unanswered, but I feel like every day we are working towards a new discovery.”