Monday, May 19, 2008

They're Heeeere

While out walking along the Ohio River yesterday, I came across this ADULT periodical cicada.  This means that the other million-or-so of his fellow insects are not far behind.  Soon the air will be filled with the buzz of their calls, and the ground beneath our feet will crunch as we tread over their cast-off skins and bodies.  

Here are few interesting cicada facts to pass along:

Cicadas are NOT locusts; in fact, locusts are more closely related to grasshoppers than to cicadas.  The cicada is a member of the leafhopper family of insects.

Only male cicadas sing.  

The sound male cicadas create comes from their abdomens, and scientists still aren't 100% sure how such a loud sound (120+ decibels) can come from such a small creature.  The noise of even one male cicada singing is enough to hurt the human ear at close range.  It is even more painful to the sensitive ears of birds and other wildlife (which is why singing is a good predator defense strategy for the cicada).  Cicadas have ears, too, so they must protect their version of an eardrum by creasing it as they sing, which keeps it from vibrating and injuring the ear.

Female cicadas mate then lay their fertilized eggs on the branches of trees.  They do this by piercing the bark with a special egg-laying device called an ovipositor.  The ovipositor can cause damage to trees by exposing them to disease, which is why we should cover our most vulnerable ornamental and fruit trees with netting BEFORE the cicadas arrive.  In Maysville, trees in the downtown area have been protected with green netting (not to be crass, but the locals are calling the netting "tree condoms").  

Once the eggs are laid, they will develop for about 6 weeks before dropping from the trees to the ground.  They will then burrow into the soil and remain there for  until they emerge to change into adults years later, sucking juices from plant roots for nourishment.  

There are many "broods" of periodical cicadas.  Broods emerge in different areas at different times.  Some broods emerge every 13 years, while others emerge every 17 years.  Some brood ranges overlap.  In Cincinnati, for example, Brood X emerged in 2004, and this year's brood (Brood XIV) will emerge there as well.  To add to the confusion, more than one species of cicada can make up a brood.  Brood XIV is made up of Magicada septendecim (85%), M. septendecula (13%), and M. cassini (5%).  

For more information on Brood XIV, please visit the University of Michigan's Cicada web site by clicking HERE.  In the meantime, enjoy this rare natural phenomenon, and keep an eye out for rare white-eyed cicadas!