Yep that what we call army worms. When they eat a wheat field they can been seen from above just marching across it mowing it down. I guess thats why they are called army worms... I have actually seen them so bad that when I got down on the ground with them I could hear them crunching, as they ate the entire field down.
I hope it was my imagination but others have told me the same story, and yes we have an airplane spray them.

Get out and fish.