Cicada on a tree
Cicadas, alternatively spelled as Cicala or Cicale, are insects in the order Hemiptera, suborder Auchenorrhyncha (which was formerly included in the now invalid suborder Homoptera).
Cicadas are in the superfamily Cicadoidea. Their eyes are prominent, though not especially large, and set wide apart on the anterior lateral corners of the frons. The wings are well-developed, with conspicuous veins; in some species the wing membranes are wholly transparent, whereas in many others the proximal parts of the wings are clouded or opaque and some have no significantly clear areas on their wings at all. About 2,500 species of cicada have been described, and many remain to be described.
Cicadas live in temperate-to-tropical climates where they are among the most-widely recognized of all insects, mainly due to their large size and unique sound. Cicadas are often colloquially called locusts, although they are unrelated to true locusts, which are various species of swarming grasshopper. Cicadas are related to leafhoppers and spittlebugs.
The male cicada has loud noisemakers called "tymbals" on the sides of the abdominal base. Its "singing" is not the stridulation (where one structure is rubbed against another) that characterizes many other familiar sound-producing insects, such as crickets. Rather, the tymbals are regions of the exoskeleton that form a complex membrane with thin, membranous portions and thickened ribs; contracting the internal tymbal muscles produces a clicking sound as the tymbals buckle inwards, and the relaxing of the muscles causes the tymbals to return to their original position, producing another click. The interior of the male abdomen is mostly hollow, which amplifies the sound. A cicada rapidly vibrates these membranes, and enlarged chambers derived from the tracheae make its body serve as a resonance chamber, further amplifying the sound. The cicada modulates the sound by positioning its abdomen toward or away from the substrate. Additionally, each species has its own distinctive song.
Average temperature of the natural habitat for the South American species Fidicina rana is approximately 29 °C (84 °F). During sound production, the temperature of the tymbal muscles was found to be significantly higher.
Cicadas sing most actively in hot weather and do their most spirited singing during the hotter hours of a summer day, in a roughly 24 hour cycle.
Although only males produce the cicadas' distinctive sound, both sexes have tympana, which are membranous structures used to detect sounds. They are thus the cicadas' equivalent of ears. Males can disable their own tympana while calling.
Some cicadas produce sounds up to 120 dB (SPL), among the loudest of all insect-produced sounds. This is notable because the song is loud enough to cause permanent hearing loss in humans should the cicada sing just outside the listener's ear. Conversely, some small species have songs so high in pitch that the noise is inaudible to humans. Species have different mating songs, ensuring that the appropriate mate is attracted. It can be difficult to determine from which direction(s) a cicada song is coming because the low pitch carries well.
In addition to the mating song, many species also have a distinct distress call, usually a broken and erratic sound that the insect emits when seized. A number of species also have a courtship song, which is often a quieter call and is produced after a female has been drawn by the calling song.
Cicada on a tree
Cicadas, alternatively spelled as Cicala or Cicale, are insects in the order Hemiptera, suborder Auchenorrhyncha (which was formerly included in the now invalid suborder Homoptera).
Cicadas are in the superfamily Cicadoidea. Their eyes are prominent, though not especially large, and set wide apart on the anterior lateral corners of the frons. The wings are well-developed, with conspicuous veins; in some species the wing membranes are wholly transparent, whereas in many others the proximal parts of the wings are clouded or opaque and some have no significantly clear areas on their wings at all. About 2,500 species of cicada have been described, and many remain to be described.
Cicadas live in temperate-to-tropical climates where they are among the most-widely recognized of all insects, mainly due to their large size and unique sound. Cicadas are often colloquially called locusts, although they are unrelated to true locusts, which are various species of swarming grasshopper. Cicadas are related to leafhoppers and spittlebugs.
The male cicada has loud noisemakers called "tymbals" on the sides of the abdominal base. Its "singing" is not the stridulation (where one structure is rubbed against another) that characterizes many other familiar sound-producing insects, such as crickets. Rather, the tymbals are regions of the exoskeleton that form a complex membrane with thin, membranous portions and thickened ribs; contracting the internal tymbal muscles produces a clicking sound as the tymbals buckle inwards, and the relaxing of the muscles causes the tymbals to return to their original position, producing another click. The interior of the male abdomen is mostly hollow, which amplifies the sound. A cicada rapidly vibrates these membranes, and enlarged chambers derived from the tracheae make its body serve as a resonance chamber, further amplifying the sound. The cicada modulates the sound by positioning its abdomen toward or away from the substrate. Additionally, each species has its own distinctive song.
Average temperature of the natural habitat for the South American species Fidicina rana is approximately 29 °C (84 °F). During sound production, the temperature of the tymbal muscles was found to be significantly higher.
Cicadas sing most actively in hot weather and do their most spirited singing during the hotter hours of a summer day, in a roughly 24 hour cycle.
Although only males produce the cicadas' distinctive sound, both sexes have tympana, which are membranous structures used to detect sounds. They are thus the cicadas' equivalent of ears. Males can disable their own tympana while calling.
Some cicadas produce sounds up to 120 dB (SPL), among the loudest of all insect-produced sounds. This is notable because the song is loud enough to cause permanent hearing loss in humans should the cicada sing just outside the listener's ear. Conversely, some small species have songs so high in pitch that the noise is inaudible to humans. Species have different mating songs, ensuring that the appropriate mate is attracted. It can be difficult to determine from which direction(s) a cicada song is coming because the low pitch carries well.
In addition to the mating song, many species also have a distinct distress call, usually a broken and erratic sound that the insect emits when seized. A number of species also have a courtship song, which is often a quieter call and is produced after a female has been drawn by the calling song.