Ever since I saw these iridescent green beetles last summer, I have been assuming they were emerald ash borers. Turns out they are commonly mistaken for the EAB, but are not. They are what is called a "six spotted green tiger beetle" and they prey on other small insects rather than trees. Whew!

(I discovered the green tiger beetle while looking at this page: http://www.fs.fed.us/r9/hoosier/docs/emerald_Ash_borer.htm )