Janesville residents won't be green with envy watching their neighbors in Lake Geneva this summer.
We've got cicadas, too.
Two Janesville Gazette staff members spotted thousands of periodic cicadas warming in the sun Friday afternoon at Camp Indian Trails on the Rock River north of Janesville.
UW-Madison etymologist Phil Pellitteri identified a photo of the critters as members of a brood that hatches only every 17 years. The cicadas had been hatched at least one day, Pellitteri said, and will spend several days hardening before they begin singing to attract a mate.
"They're just trickling so far," Pellitteri said. "This will continue to build."
There are dozens of cicada broods in North America, each with different life cycles, patterns and songs. Wisconsin also hosts a brood called "dog days" cicadas, which whine and buzz in the trees late every summer.
On the other wing, periodic cicadas stay underground for years in order to outsmart their predators. They also overwhelm predators by hatching in numbers 100 times greater than dog days cicadas.
The sighting of 17-year cicadas north of Janesville was a surprise to Pellitteri. The broods have been hatching in the same areas for two million years, and this brood is normally located in parts of Walworth, Racine and Kenosha counties and Chicago.
"It would be a little surprising," Pellitteri said before identifying the Gazette's photo Friday afternoon. "Everything I'd heard about was south of Janesville."
But it's not a huge surprise, he said, because periodic cicadas prefer old, undisturbed wooded areas like those around the river.
Pellitteri said it will be late June before the cicadas hit the "dramatic" population peak Lake Geneva residents have been anticipating.
For the next two weeks or so, mature cicadas will emerge from the soil, shed their skins and begin searching for a mate. They have to hurry, because adult cicadas live no more than six weeks.
One female lays up to 600 eggs on a twig where the eggs mature for up to 10 weeks.
Cicadas "nymphs" fall from the mature eggs and burrow into the ground. The nymphs, which are 2 to 3 millimeters long, attach to a tree root and grow for years, depending on the brood.
Adult cicadas do not eat crops and are not poisonous.
