Voracious

I was checking out a small crabapple that seemed to be losing its leaves prematurely.  I didn't notice this guy until he stung me.  The crabapple wasn't losing its leaves, they were being eaten off.  He had five buddies helping him.

Eastern saddleback caterpillar, Acharia stimulea

Here's an end view.   (I'm not sure which end.)

I turned the leaves upside down to take the photos, the caterpillars were on the undersides.