Last summer I kept seeing these purple boxes up in trees here and there. I'm in Maryland. These boxes sort of looked like kites stuck up in trees.
Come to find out they place these boxes by Ash trees to catch these beetles. They were also trying to determine how many beetles are out there.
Here's a link that's pretty interesting and provides more info.
http://www.hgic.umd.edu/content/emeraldAshBorer.cfm
On another note, they can take the Stink Bugs with them. Another up and coming pest.
http://www.hgic.umd.edu/content/brownstinkbug.cfm