|Image: James Jordan|
Noise! Loud, rasping, ear-splitting noise the kind of which one usually encounters when the guy next door is practising his washboard playing. That is the major contribution Cicadas have given the world. Noise is what they do to attract a mate and if you annoy one, it's also what they'll do to repel the enemy.
|Image: Tony Willis|
Chorus Cicada (Amphipsalta zelandica), so named for their synchronised singing
There are over 2,500 species of Cicada in the Cicadidae family. It's one of those "every continent except Antarctica" deals, where pretty much every part of the world has at least one species of resident Cicada if not several hundred in the tropics.
The Double Drummer (Thopha saccata) is Australia's largest Cicada.
The wings alone are over 6 cm (4in) long!
|Image: Neil Skene|
Green Grocer (Cyclochila australasiae) and its three ocelli
|Image: Chaval Brasil|
Weird face mask thing
Cicadas are members of the order Hemiptera, known as true bugs. Or just bugs if, like me, you don't commonly call all sorts of other things "bugs". Hemiptera includes lots of familiar beasties like Shield Bugs, Stink Bugs and Aphids... the kind of thing you'll often see lounging around on your plants drinking up their vital fluids.
Cicada drinking a tree
Also a bit like prison is all the faeces that gets thrown around. Tree sap is so full of water that Cicadas squirt out the excess with remarkable force, like one of those Super Soaker water guns. It's absolutely appalling behaviour. Don't try it at home! Or, alternatively, ONLY try it at home! It'll get you kicked out of most other places. And if it doesn't, you probably shouldn't be in places like that anyway.
The tree says "ouch"
VULNERABILITY! It's a dirty word, ain't it? If you're a wolf, it happens when you're demonstrating your submission to the alpha wolf and you're on your back showing off your juicy, throbbing neck. One would like to think that humans don't do that so much, that we show vulnerability in loving relationships, when you feel completely comfortable or when you had a really cool accident.
It's unfortunate then that a comfortable Cicada may well bite you. If you find one relaxing on your arm and staying there for a long time, you might think that you're developing a trusting relationship with it. This illusion will be shattered when it decides that it's been sitting here unmolested for so long that you're probably a tree. Commence exploratory drilling!
Cicadas aren't keen on biting people. It doesn't seem to be a defence mechanism and the proboscis is so long for getting deep into plants that it looks too ungainly for a quick attack. But... you know. Perhaps one day a Cicada will get right through the skin and start slurping up blood and be like "this is really great sap! I love it!" That would be unfortunate for all of us.
Until that fateful development, the main thing a Cicada will do when captured by a predator is scream in outrage. "How DARE you! Do you know who I am?" That's probably a rough translation of the noise they make.
Cicadas don't stridulate like grasshoppers and crickets, stridulation being when one part of the body is rubbed against another, like part of a wing on part of a leg. Instead, they have little structures called tymbals.
Video: Ace Jackalope
It looks like a stripy membrane hidden away in the abdomen. The stripiness comes from the fact that parts of it are very thin while other parts are thickened. Muscles make this structure buckle upward and produce a click, then buckle down and produce another click. You can do a similar thing with a tin!
Male Cicadas have a lot of empty space in their abdomen to make the sound resonate. Not only does this allow some Cicadas to be amongst the loudest of all insects, it also enables them to attract a mate. Which is more to the point. Cicadas don't need adulation from the crowd, they just want a mate. Such wisdom!
|Image: Stephen Begin|
Try a triple-blade for an extra close shave
Cicadas, like all true bugs, belong to the superorder of insects known as Exopterygota. It means that the youngsters aren't maggots, grubs or caterpillars and instead look quite a lot like their parents.
|Image: Camponotus Vagus|
Cicada nymph's claw. Erk!
Adult emerging from the final moult
Empty skin covered in soil
While most Cicadas live for just a few years, there are a few with a lifespan of over a decade. These are the remarkable Periodical Cicadas of the wonderfully named genus Magicicada. There are seven species, all in eastern United States and four of them have a 13 year lifecycle, the other three a 17 year lifecycle. They spend almost the entirety of this time as a nymph underground.
|Image: Blue Yonder|
This regular plague is thankfully not as devastating to plant life as it looks like it ought to be. It is however a massive feast for all sorts of hungry animals great and small. It seems that these Cicadas survive by providing a buffet so incredibly satisfying that even after all and sundry have had their fill, there are still millions of adults laying their eggs and laying the groundwork for next time.
Magicicada, recently emerged
Oddly enough, there is one who has managed to take full advantage of the Periodical Cicada and align itself to their cycles impeccably. It's a fungus called Massospora cicadina, and its spores are able to lie dormant in the ground for the required 13 or 17 years.
Magicicada, ready for action
It's grizzly stuff, but someone has to strike one back for the trees!