Wherever there are old trees (at least over 17 years old), there will be some cicadas.  Very old established forests will see many cicadas, but they will not be harmed at all. New developments will see few to none. 

Here is some brief info and answers to questions: https://extension.umd.edu/hgic/topics/cicadas

And here is more interesting info: https://extension.umd.edu/ipm/brood-x-periodical-cicadas

Enjoy them as a brief oddity and the weirdness of Mother Nature. 

Ellen