This article, by Tyler Rushmeyer, appeared in the local news section of today's Pioneer Press:
Racket bugging residents: Night music made by katydid colony
Many White Bear Lake residents were baffled when they started hearing a new sound reverberating through their neighborhoods.
As night falls, a loud "yack, yack" sound has filled the air. "It sounds like a tropical rainforest on my block," said White Bear Lake resident Mark Nevala, one of several people to call city officials asking about the noise.
The culprit: katydids, loud insects performing mating calls by rubbing their wings together. The mating season should last into early October.
Closely related to grasshoppers and crickets, katydids are spread throughout Minnesota. The bugs residents are hearing are the northern katydid species, said Dick Oehlenschlager, assistant curator and collections manager for biology at the Science Museum of Minnesota.
"They move in colonies and shift every year, and this year their colony seems to have taken residence in the Twin Cities area," he said.
The insects--about 2 inches long and bright green, with long, coiled antennae--are near-motionless during the day and reside on the leaves of trees. But soon after dusk, they become active. They are difficult to spot, Oehlenschlager said, which is why many people are confused about where the noise is coming from.
"Even I didn't know what I was hearing the first couple times I came in contact with them," Oehlenschlager said.
Look for our new fall phenology section, featuring other seasonal behaviors of insects and birds, coming to the Mississippi River Gallery and the Buzz website after next week.