As we were collecting traps a couple weeks ago we discovered one had fallen in the water over the past week. A large insect was swimming inside, which I recognized to be a giant water bug, or Belostomatidae. We christened it Stevie Nicks, and brought it back to the lab.
I did a bit of research and found out they can eat fish and other vertebrates, so we brought a fish in from the field. The fish died en route, so I held it in front of Stevie Nicks with a pair of forceps. Stevie Nicks grabbed the meal and pierced the eye of the fish with a stylet common to all Hemiptera. I did some reading and apparently they eject digestive acids via the stylet and drinks the prey, much like a spider.
Unfortunately I did not keep the container as clean as I should have, and Stevie Nicks passed away over night. Water mold got the best of it.