Cicadas to return this spring

They don't bite or sting, but the 13-year cicada scheduled to re-emerge this spring is certain to make plenty of racket.

 

"Cicadas are not pests, so there is no reason for alarm," said Nancy Hinkle, an entomologist and professor at University of Georgia. "This emergence is also a great opportunity for an up-close view of this amazing phenomenon."

The fat, red-eyed insects made their last appearance across Georgia and South Carolina's Piedmont regions in 1998 and won't return until 2024.

"Children who experience this year's cicada emergence will not see this group of cicadas again until they themselves are adults," Hinkle said.

De Anna Beasley, a University of South Carolina doctoral student who studies the insects, said the big bugs could arrive any day now.

"We expect them to appear during the first warm evenings, possibly starting as early as this week," she said.

Scientists refer to them as "periodical cicadas," as opposed to an "annual" or "dog-days cicada" found in much smaller numbers.

"Periodical cicadas emerge in the spring, have black bodies, bright red eyes and orange-veined wings," Hinkle said, "while dog-day cicadas emerge in summer, are larger and have green bodies and black eyes."

Once the 13-year cicadas hatch, their above-ground lives are short, lasting no more than four to six weeks -- just enough time to mate, lay eggs and die.

Beasley said the reason they lie dormant for so long, and then hatch in huge numbers, is a mystery of nature.

One theory is that mass numbers hatching all at once increases the chances that some will survive.

"The mass numbers help them survive and overwhelm predations by birds and other animals that eat them," she said. "They seem to have no fear or instinct to escape."

Although only the males make the insect's well-known screeching sounds, the noise can become deafening.

The noise is created by the vibration of a membrane on the insect's thorax. "When you get a bunch of males together, it can become very, very loud," she said.

Part of Beasley's research involves using residents to help track the location, time and density of cicada emergence.

"We're very interested in understanding how past land use will affect their emergence," she said.

"We know a good bit of their life cycle revolves around trees so we will be looking to see how changes -- like from agricultural to suburban -- can affect their density."

More information on the 13-year cicada, and the observer program, is available on Beasley's Web site, cricket.biol.sc.edu/cicada/index.html.

University of Georgia scientists are also mapping this year's cicada emergence. Hinkle asks that people who photograph or otherwise count cicadas e-mail images or details to Insects@uga.edu.

Reach Rob Pavey at (706) 868-1222, ext. 119, or rob.pavey@augustachronicle.com.