A Giant Bug

Last night, I dreamed that I was living in my parents' old house in Chesapeake, Virginia and my friend Liz was over.  We discovered two large bugs that resembled stink bugs, but their backs had these knobby ridges on them and they were an iridescent pink and purple.  One was smaller than the other.  We were able to shoo the smaller one back outside, but faced quite a challenge with the large one, which was about 8" from nose to butt.  Liz managed to get it into a medium-sized box, and we tipped it sideways to see its underbelly.  It had pincers and then a row of sharp teeth, and it made motions with its pincers at us.  Liz closed the lid and we left the room for a few minutes.
When we came back to dispose of it, the lid was off of the box and the creature was gone.