The Music of Flight
When insects fly, they produce sound.
Sometimes the sound is just a series of clicks. That is the case with a few grasshoppers that produce sound with a special mechanism on their wings.
Most sound produced by flying insects, however, is due to the vibration of their wings. Some insects, such as many butterflies and moths, flap their wings so slowly that the sound produced is inaudible. Soft wings flapping at a mere five to 10 beats per second are hard to hear. Except, as cartoonists sometimes suggest, by someone suffering from an extreme headache!
Most insects vibrate their wings much faster than the butterflies and, as a result, produce perceptible sounds. This sound, sometimes called the music of insect flight, is put to good use by the insect. For instance, many animals will recognize a beat frequency of around 435 beats per second as the buzz of bees. This wing-beat frequency provides a measure of protection to bees as well as to other insects with a similar wing-beat frequency. The sound suggests the possibility of getting stung.
The highest pitched insect flight sounds are produced by mosquitoes and midges. These small insects vibrate their wings around 1,000 times per second, which is fast enough to produce a high-pitched whine. It is a sound that is dreaded by anyone who hates to be bitten by a hungry female mosquito.
The wing-beat frequency of female mosquitoes serves a biological function beyond flying. It is an attractant for male mosquitoes. Various species of mosquitoes have different wing-beat frequencies. Consequently, males that are not tone deaf respond only to those frequencies produced by females of their kind. However male mosquitoes can be fooled. These love struck males will congregate on a screen next to a tuning fork vibrating in the proper frequency.
The sound of insect flight has not gone unnoticed by music composers over the ages. Nicolas Rimsky-Korsakov composed Flight of the Bumblebee, in which the high-pitched song of the queen is heard among the lower frequency sound of the workers. Joseph Strauss put in place the music for Dragonfly. In Dance of the Mosquito, Anatol Liadov uses violins to produce the sound of the mosquito.
Classical music or not, there is just something about the sound of a mosquito that makes me a little uneasy. Unless of course the mosquito is a male and can't bite anyway!