We had bazillions of them here in Central PA. There was no real damage done (if you don't count the pencil sized holes they emerge from) and there wasn't much of a mess. The leaf tips on some of the limbs on the trees turned brown, but nothing major.
The sound was something else. In the evening it was the loudest. It was amazing listening to the sound of 1000s of insects rising and falling in unison. In Washington DC, they were so loud they 'violated' noise laws because the exceeded 90 db.
Our dogs liked to eat them, too, so we had to watch out for that. Didn't want partially digested cicadas appearing on a floor. /forums/images/graemlins/tongue.gif
My inlaws, who live just a few miles from us, did not have any cicadas and actually came to visit us, just to see and hear them. Their housing development is less than 17 years old, so the ground was disturbed, killing all the 'hibernating' cicadas.
