Cricket Communication

Crickets don't sing like birds, their songs are not produced by vocal cords. Instead, they chirp.

Moreover, only males chirp.

They do so by rubbing their forewings together; the forewings (also known as tegmina) are specialized, with a file (a row of cuticular teeth) and a scraper. The cricket rhythmically moves the scraper on one wing against the file on the other, producing sound pulses. Several sound pulses make up a chirp. Each wing also has an area known as the “harp” which resonates and amplifies the sound.

Female wings lack these special structures.

Males chirp, or sing, for different purposes. The calling song is species-specific in both frequency and temporal pattern and is used to attract females of the same species for mating. Females move towards the source of songs they prefer, a phenomenon known as phonotaxis.

The temporal pattern of the song results from a set of neurons in the central nervous system (central pattern generator), and a command neuron in the brain controls the central pattern generator.

Most crickets chirp at different rates depending on the temperature, with higher rates occurring at higher temperatures. “Temperature coupling” occurs, such that male chirps at a particular temperature can be perceived by females of the species at that same temperature.

Once a female has reached a male, he switches to a softer and more variable courtship song.

Males also have a “rivalry” song, used in aggressive interactions with other males, particularly after winning a fight.

Crickets’ ears are found on the front legs; their hearing is “tuned” to the fundamental frequency of the species’ calling song.

Example of cricket song. Each chirp is made up of three sound pulses that are 10 ms long:

Chirp Chirp