Few sounds are more annoying than the buzzing of a mosquito. Listening to it reveals us and puts us on notice. We look around and try to locate the insect to catch it before it bites us. Its sound can drive us crazy, hence the African proverb “if you think you are too small to do great things, try sleeping with a mosquito in a room“, however it is music for a mosquito.
Surprisingly, despite their small size, mosquitoes are the insects with the largest number of neurons in the Johnston’s organ, which would be the equivalent of our auditory system. In the case of the yellow fever mosquito (Aedes aegypti), it has been reported that males have more than 15,000 neurons, while females have approximately half of the neurons dedicated to capturing and interpreting sounds. They have an extremely sensitive “ear” as it is essential for their reproduction. The buzz that makes us so nervous for them can be a love song.
Mosquitoes sing before mating
When the buzzing of mosquitoes is analyzed, it can be seen that the males emit a sound of about 600Hz when flying. The females have a much lower pitch, around 400Hz. In part it is due to the difference in size between them: the females are larger, their wings too, so they do not have to flap their wings as fast as the males to maintain their flight. Look at the flight of birds with large and small wings, and you will see that the frequency with which they beat their wings is very different. The same thing happens between males and females of the same species of mosquitoes. However, when males and females get together something surprising happens: they adjust their frequencies in order to produce a common tone that can reach 1,200Hz.
Until not so long ago it was thought that insects were great masters of timing and rhythm when it came to mating, just think of the summer concerts of cicadas and crickets, but they did not control the pitch very much, however the mosquitoes did. make. In fact, when both sexes adjust their frequencies, the interval between the pitch of the male mosquito and that of the female mosquito comes very close to what musicians call a perfect fifth. For centuries, composers considered the fifth interval to be the most euphoric of all, something that seems to work in the case of mosquitoes: if the male manages to create a duet with the female, creating a fifth interval, the chances of being chosen and reproduce multiply. In other words, the female tends to choose the male who best sings her duet.
Can we disharmonize their buzzing?
The males of many species of mosquitoes usually form swarms in which the females enter to choose one. These swarms can be made up of tens or hundreds of males, varying between species, but in all of them they are a sound environment that makes communication between the female and a male difficult. How do they communicate and recreate their particular duos when there is so much noise around them? Their hearing systems have evolved in such a way that males and females also differ in how they filter, amplify and process sound, allowing each sex to focus on the most relevant information.
All this knowledge, beyond the pleasure of knowing, is studied to find the weak points of the mosquitoes on which to act when managing their populations. There are not a few works that point out that the communication system and the auditory systems of mosquitoes can be viable targets in future control programs. Will mosquitoes be genetically edited that don’t “hear” each other and don’t reproduce? Will ways be found to interfere with communication between males and females?
Cator LJ, Arthur BJ, Harrington LC, Hoy RR. 2009. Harmonic convergence in the love songs of the dengue vector mosquito. Science 323: 1077-1079
Gage G. 2018. The real reason why mosquitoes buzz. DIY Neuroscience TED series
Gibson G, Russell I. 2006. Flying in tune: sexual recognition in mosquitoes. Current Biology 16: 1311-1316
Robert D. 2009. Insect bioacoustics: Mosquitoes make an effort to listen to each other. Current Biology 19: R446-R449
Su MP, Andrés M, Boyd-Gibbins N, Somers J, Albert JT. 2018. Sex and species specific hearing mechanisms in mosquito flagellar ears. Nature Communications 9: 3911