Insects That Sing

Significance

• Insects do not sing or make melodic sounds for the enjoyment or annoyance of human beings. When insect songs are audible, the sounds indicate that mating season is in effect. Entomologists, or scientists who study insects, inform the general public that songs are predominantly sung by adult males of the insect species. They sing to attract female mates and defend home territories against intruders. Of all the song-making insect species, katydids offer an exception to the gender singing rule. Female katydids sing to the males of the species as well.

Habitats

• Katydids live among tree tops and shrubs and being nocturnal, they are heard at night. Adaptable creatures, katydids live in the tropics, temperate conditions and dry, hot areas like deserts. Crickets and grasshoppers are similar to katydids but are not all nocturnal. They do not live among trees but are adapted to low grasslands, fields, road sides and dark, protective areas under logs and stones. When cicadas emerge from underground, they live on trees and croon morning, noon and night.

Sound-making

• Katydids and crickets both sing to other members of their species by rubbing their front wings together. One wing has a sharp edge while the other has a structure like a file. The filing action makes the wings vibrate which makes the sound. This way of making sound is called stridulation. Grasshoppers also create sound with stridulation but instead of rubbing their wings, they rub their legs on their wings. In sharp contrast to katydid and cricket songs, grasshopper sounds are barely audible to humans.

Sound-Making Exceptions

• The songs of band-winged grasshoppers do not come from rubbing their wings against their legs. Their songs occur when they are in flight and their wings are pulled tight. Their wings pop and snap against the wind creating their melodies. Instead of stridulation, this method of sound-making is referred to as crepitation. Cicadas have sound-producing muscular organs inside their abdomens called tymbals. Multiple contractions and relaxation of tymbal organs create buzzing. The buzzing is amplified by the anatomy of the abdomen.