From what I know about the subject, this is what is called Brood II. There are several different Broods that appear periodicaly over time. The last time this appeared, from what I can find out, was 17 years ago and the next time it will happen is meant to be 2030. I originally didn't take that many pictures of this event as I found the insects to be somewhat of a nuisance and there were already many pictures documenting the event. The more I thought about it, the more I wanted to try to get some cool shots as this really isn't an event that happens often.
Outside of my office there is a large stump that is almost covered in cicadas so I went out and captured a few interesting ones on the stump and walls of the building.