I have been scouring all the insects books in our library (I'm a librarian), and cannot find out the scientific name of this particular insect. As a child (I live in NYC, by the way), we used to call them 'helicopter bugs.' But when I research under that name, a dragonfly type of insect comes up.

This particular critter is quite large and has a beetle-shaped, oval body. It's kind of a fat little thing (just not so little). Its exoskeleton is metallic looking (that's what makes them easy to identify) and they are QUITE loud. I heard one buzzing around on the sidewalk across the street from where I was standing!

I was just wondering if anyone could help me out. I was thinking maybe they're related to the cicada in some way, but I can't be sure. I don't even know where to look :(

Thanks in advance!!

Frustrated Jess