Periodical cicadas of 2011 expected to emerge in May

COLUMBIA — The countdown is on. 

Columbia is only weeks away from experiencing an event not seen —or rather, heard — since 1998.  It will be loud, stinky and, for some, even frightening. This deafening chorus is imminent as the warmer days of May approach.

Prepare yourselves — the periodical cicadas are coming.   

Brood 19, or the Great Southern Brood, of periodical cicadas is scheduled to emerge en masse throughout central and northern Missouri next month, Gene Kritsky, editor-in-chief of American Entomologist, said. 

Thousands of cicada nymphs will crawl out of the ground when the soil reaches about 65 degrees. The nymphs will climb trees, shed their skins and begin the noisy process of searching for a mate.  The males will sing from about 10 a.m. until dusk every day for weeks before they die off, Kritsky said. 

Historically, 13-year cicada broods emerge around May 15, Kritsky said. His date is an estimate and subject to change depending on temperatures and rainfall.

“Cicada emergence is really all tied to the soil’s temperature,” Kritsky said.

When the cicadas do emerge, certain areas of Columbia could experience a deafening chorus. 

“In places where there are older, well-established trees, you could get up to 85 decibels,” Kritsky said. “To put that in perspective, when a jet is flying overhead that is usually between 60 and 70 decibels.”

Individual cicadas are not tremendously loud, said Johannes Schul, an MU biology professor. But since they will emerge in such large numbers and gather in groups, Schul said, there is no doubt the cicadas will produce an “enormous chorus” throughout Columbia.

“It won't damage anyone’s hearing,” Schul said. “If we were exposed to those levels of noise for years at a time, then we might face an effect, but this outbreak is short and will not have any adverse health effects aside from stressing a few people out.”

How loud the chorus will be depends on the concentration of cicadas and how suitable an area is for mating. Areas that have undergone development in the last 13 years may not see any cicadas emerge.

“If a developer has come in and knocked down all of the trees in the area since the last emergence, then the only cicadas you will see are the ones who fly in,” Kritsky said. 

Newer developments aren't necessarily safe from the cicada onslaught, Kritsky said.  

“Although cicadas may not emerge there, they are attracted to young trees in full sun surrounded by low-lying vegetation, similar to the kinds of trees you see in newer developments," Kritsky said. "The cicadas will seek out these kinds of trees and congregate there in large clusters.”

Large clusters of cicadas, or leks, are particularly fond of small trees such as crab apples, elms or Bradford pears, Kritsky said. 

Periodical cicadas survive on a strategy of satiating their predators. They emerge in such large numbers that there will always be some left over to reproduce. After a while, predators get tired of eating the cicadas and leave them alone. 

“If you walked outside and found the world swarming with Hershey Kisses, eventually you would get so sick of Hershey Kisses that you would never ever want to eat them again,” Kritsky said.

The sight and sound of the cicadas will stick around for four to six weeks while the insects mate and the females lay eggs in slits cut into the branches of small trees before their life cycle comes to an end.     

"When they die off, they start decaying, and since it is hot it can get really stinky," Kritsky said.  

MU is scheduled to hold the 13th International Meeting on Invertebrate Sound and Vibration near the end of the cicadas' life cycles. The meeting will take place June 4 to 7 and attract nearly 100 researchers, professors and students from around the world, Schul said.  

The meeting is held every two or three years and covers anything related to sound and vibration communication by invertebrates.