Cicadas 2011: Top 13 Things To Know About These Noisy Insects

May 12, 2011 — -- They're noisy. And can be a nuisance. But for the most part they are harmless. Thankfully, they only come out every 13 or 17 years.

The dreaded cicadas have emerged in middle Tennessee this week. Brood XIX to be exact.

This particular brood is of the 13-year variety, as are most of the cicadas in the South. Around cities like Nashville, the cicadas are being spotted emerging from their eggs, clinging to trees and flying around. And soon the air will be filled with an almost deafening, high-pitched shrill as the males sound their mating call.

"It's not something to fear, it's actually an exciting thing to see," said Dr. Frank Hale, an entomologist with the University of Tennessee agricultural extension service.

Hale has been studying insects for more than 30 years. He sees this emergence as a teaching opportunity, because there are a few misconceptions about cicadas.

So here are 13 things, give or take about a dozen, that you never knew about these noisy visitors.

The females then begin laying eggs in the limbs of smaller trees, as many as 400 to 600 eggs at a time. After six to seven weeks the eggs hatch and the "nymphs," as they are called, drop to the ground and burrow into the soil where they remain for 13 to 17 years.

It is the laying of eggs that poses a danger to small flowering and fruit trees. A female can make five to 20 slits in one branch to deposit her eggs. That causes the branch eventually to wilt and die.