HANNIBAL, Mo. (AP) -- There's a high-pitched buzz in the ears of many Missourians this year -- the result of the once-every-17-year emergence of a red-eyed insect.
Periodical cicadas spend the bulk of their life underground feeding on the sap of trees before emerging after 17 years for a noisy end to their life.
"When they come out they probably dont live very long. If they live more than a week that would be unusual," said Gerald Burkett, a biology professor at Hannibal-LaGrange University who holds a doctorate in entomology. "Their main purpose is to find a mate, mate and then the female to lay eggs."
The courtship song is what can drive humans crazy.
Burkett knows firsthand what its like to be surrounded by a choir of cicadas.
"I remember when I first came to the college there was a group of them which came out back on the nature trail. It was so loud and deafening it would hurt your ears. Its a high pitched and loud sound," Burkett told the Hannibal Courier-Post.
While cicadas pose no threat to humans, they can cause damage to trees and shrubs. The females will crawl up branches and cut slits in finger-sized twigs to deposit eggs. A female deposits 24 to 28 eggs beneath the bark, and can make as many as 20 slits before going to another twig. Each female can lay 400 to 600 eggs, which remain on twigs for six to 10 weeks before hatching.
The egg-laying process can weaken smaller stems, allowing wind bursts to snap them off, said Chris Starbuck, a University of Missouri extension specialist for woody ornamentals.
After the eggs are laid and the larva hatches, they fall to the ground and dig into the soil where they will eat and wait 17 years to emerge again. The cicadas come out of the ground still wearing their nymphal skin which will pop open. After leaving their nymphal skin, the cicadas are white. As the bugs harden, their bodies change to black and they develop red veins in the wings.
Burkett said the 17-year cicadas should not be confused with the dog-day cicadas, which are heard each August and September. He said periodic cicadas are smaller than the cicadas that Missourians normally see in late summer.
Information from: Hannibal Courier-Post, http://www.hannibal.net
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