Japanese beetles
I caught a nice 18 inch brown trout a few summers back that was gorging on japanese beetles. I have caught countless bluegills that were full of them. I think the idea of putting traps that cause the beetles to fall into the water is ingenious. If I had a pond I wouldn't hesitate to rig up some of these traps to help make the beetles more available to the fish. I remember we had problems with beetles in this part of NC when I was a kid, but they haven't been that much of a nuisance in the past few years. (now the fire ants and yellow jackets, that's a different story)
Life, Liberty, and the pursuit of crappie nests