Sunday, September 23, 2007


What in the world is a Cicada???

This spring I heard a rumor that the Cicadas were hatching around here. I had never actually SEEN a live cicada, or even a picture of it. That is until yesterday. Because yesterday I stumbled across one at the edge of Great Bay while oystering...

It was so kind as to allow me to take a few pictures...and let me hold it . The whole time I was holding him, he made that crazy loud buzzing noise that Cicadas make...

So, here is the Cicada from yesterday:

And here is a description of what the heck they are!

A Cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha, in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the globe, and many remain unclassified. 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 remarkable acoustic talents. Cicadas are sometimes colloquially called "locusts",[1] although they are unrelated to true locusts, which are a kind of grasshopper. They are also known as "jar flies". Cicadas are related to leafhoppers and spittlebugs. In parts of the southern Appalachian Mountains in the United States they are known as "dry flies" because of the dry shell they leave behind.

Cicadas do not bite or sting, are benign to humans, and are not considered a pest. Many people around the world regularly eat cicadas: the female is prized as it is meatier. Cicadas have been (or are still) eaten in Ancient Greece, China, Malaysia, Burma, Australia, Latin America and the Congo. Cicadas are employed in the traditional medicines of China and Japan for hearing-related matters.[citation needed]

The name is a direct derivation of the Latin cicada. (In classical Greek it was called a tettix, and in modern Greek tzitzikas.)

Male cicadas have loud noisemakers called "timbals" on the sides of the abdominal base. Their "singing" is not the stridulation (where two structures are rubbed against one another) of many other familiar sound-producing insects like crickets: the timbals are regions of the exoskeleton that are modified to form a complex membrane with thin, membranous portions and thickened "ribs". Contracting the internal timbal muscles yields a pulse of sound as the timbals buckle inwards. As these muscles relax, the timbals return to their original position. The interior of the male abdomen is substantially hollow to amplify the resonance of the sound. A cicada rapidly vibrates these membranes, and enlarged chambers derived from the tracheae make its body serve as a resonance chamber, greatly amplifying the sound. They modulate their noise by wiggling their abdomens toward and away from the tree that they are on. Additionally, each species has its own distinctive song.[1]

Although only males produce the cicadas' distinctive sound, both sexes have tympana, which are membranous structures used to detect sounds and thus the cicadas' equivalent of ears. Adult cicadas have a sideways-ridged plate where the mouth is in normal insects.

Some cicadas produce sounds louder than 106 dB (SPL) "at close range", among the loudest of all insect-produced sounds.[4] Conversely, some small species have songs so high in pitch that the noise is inaudible to humans[citation needed]. Species have different mating songs to ensure they attract the appropriate mate. The song intensity of the louder cicadas acts as an effective bird repellent.[citation needed] Males of many species tend to gather which creates a greater sound intensity and protects against avian predators.[citation needed]

In addition to the mating song, many species also have a distinct distress call, usually a somewhat broken and erratic sound emitted when an individual is 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.

The song of the cicada is a favorite sound effect used by filmmakers and animators as a means of representing silence, pathos, and the great outdoors.

After mating, the female cuts slits into the bark of a twig, and into these she deposits her eggs. 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. Most cicadas go through a life cycle that lasts from two to five years. Some species have much longer life cycles, e.g. the Magicicada goes through a 17- or occasionally 13-year life cycle. These long life cycles are an adaptation to predators such as the cicada killer wasp and praying mantis, as a predator could not regularly fall into synchrony with the cicadas. Both 13 and 17 are prime numbers, so while a cicada with a 15-year life cycle could be preyed upon by a predator with a three- or five-year life cycle, the 13- and 17-year cycles allow them to stop the predators falling into step.[5]

The insects spend most of the time that they are underground as nymphs at depths ranging from about 30 cm (1 ft) up to 2.5 m (about 8½ ft). The nymphs feed on root juice and have strong front legs for digging.

In the final nymphal instar, they construct an exit tunnel to the surface and emerge. They then moult (shed their skins), on a nearby plant for the last time and emerge as adults. The abandoned skins remain, still clinging to the bark of trees.


bs said...

yay! i love cicadas... i grew up in dallas, but would you believe there are none here in northern california, where i live now? i miss that noise... it's a fixture in anime i've noticed, evidently they have 'em in japan too!