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Last updated on April 19, 2014 at 18:42 EDT

Cicada

A cicada is any of several insects of the order Hemiptera, suborder Homoptera, with small eyes wide apart on the head and transparent well-veined wings. Cicadas live in temperate to tropical climates.

Taxonomy

There are many thousands of cicada species. The largest are in the genera Pomponia and Tacua. There are some 200 species in 38 genera in Australia, about 100 in the Palaearctic and exactly one species in England, the New Forest Cicada (Melampsalta montana), which is widely distributed throughout Europe, where about 2,000 species are known (some 600 in Germany alone).

Description

Adult cicadas, called “imagines”, are usually between 1 to 2 inches (2 and 5 cm) long, although there some tropic species that reach 6 in (15 cm), e.g. the Pomponia imperatoria from Malaysia. Cicadas have prominent eyes set wide apart on the sides of the head, short antennae protruding between or in front of the eyes, and membranous front wings. Cicadas are also one of the only insects known to cool themselves by sweating.

Male cicadas have loud noisemakers called “tymbals” on their sides. Their “singing” is actually a kind of stridulation: they vibrate these membranes with strong muscles; their body serves as a resonance body greatly amplifying the sound. Some cicadas produce sounds louder than 100 dB. (This amazing sound has frequently inspired haiku poets in Japan to write about them.) They modulate their noise by wiggling their abdomens toward and away from the tree that they are on.

The fact that only males produce the cicadas’ distinctive sound prompted Xenophon to remark “Blessed are the cicadas, for they have voiceless wives.”

Life cycle

Most cicadas go through a life cycle that lasts between two to five years. Some species have much longer life cycles, e.g. the Magicicada goes through a 13- or even 17-year life cycle.

Most of this time, the animals spend underground as nymphs at depths ranging from about 1 ft (30 cm) up to about 8½ ft (2.5 m). The nymphs feed on root juices and have strong front legs for digging.

In the final nymphal instar, they construct an exit tunnel to the surface and emerge. On a nearby plant, they molt one last time and emerge as an adult. When they molt, they shed their skins, and the abandoned skins can often be found left on trees, still clinging to the bark.

Only the males have tymbals and “sing” to attract females. After mating, the female cuts slits into the bark of a twig and deposits her eggs there. She may do so repeatedly, until she has laid several hundred eggs. When the eggs hatch, the newborn nymphs drop to the ground, where they burrow and start another cycle.

Cicada