Mason City Globe Gazette, IA
09-27-06
Cicadas extra buzzy this year
By JENS MANUEL KROGSTAD, For The Globe Gazette
WATERLOO — In September, as the autumn frost nears, cicadas reach the
coda of their song.
While their signature buzzing has cooled off with the temperatures, this year
nonetheless marked an unusually active one for cicadas. The Iowa Department
of Natural Resources reported dozens of calls this summer, especially from the
state’s northern counties, about the insect’s increased volume.
Ken Holscher, Iowa State University entomology professor, said several
years of warmer-than-average winters probably played a significant role in the
apparent population boom. While it sounded like a busy cicada year, he said it’s
impossible to know for certain because no one tracks cicada populations.
“Anytime we have even one or more mild winters, numbers are likely to go up.
The fact that some people may be seeing the result of that is no surprise,” he
said.
Iowa DNR reports increased activity has been reported by citizens across the
state, though the calls were focused mainly in northern Iowa.
“In select locations cicadas have recently emerged by the hundreds and are
covering outbuildings, trees and sidewalks,” said Lowell Washburn, Iowa DNR
spokesman.
While no such dramatic displays were found in Black Hawk County, University of
Northern Iowa biology professor John Ophus said that didn’t make the critters
any less noticeable in the Cedar Valley.
“Many people have said the call of a cicada sounds like whining or chirping; I
think it sounds like a car alarm on speed,” he said.
Cicadas don’t produce their signature buzz by rubbing two parts of their body
together like grasshoppers. Rather, they use tymbals, two drum-like structures on
their abdomens that vibrate into a chamber to amplify the noise.
Despite all the noise, Holscher said, only the males make the sound, a fact that
has produced some colorful, if not entirely appropriate, sayings.
“There’s an old, ancient saying, ‘Happy are the cicadas lives for they have
voiceless wives,’” he said.
Wherever cicadas are found, chances are killer cicada wasps, the largest wasp
in Iowa, are nearby. Holscher said he probably received more calls about the
scary-looking wasp than about cicadas this summer. Though possessing a
dangerous name, the insects are harmless to humans. He said they earned the
name because of the way they hunt cicadas —- the wasp paralyzes the cicada
with its sting for breeding purposes.
“Then the killer wasp grabs onto the cicada, takes it underground and lays one
egg on it. Because that cicada is not dead, just paralyzed, the larvae hatches and
feeds on it,” he said.
Jens Manuel Krogstad is a reporter for the Waterloo-Cedar Falls Courier. Reach
him at (319) 291-1580 or jens.krogstad@wcfcourier.com.