Not a caterpillar

I was looking for caterpillars yesterday, using my sweep net to sample some tall grasses along the side of the road. I threw this guy into my jar, and it wasn't until I took it out for a photo that I realized it wasn't a caterpillar at all!
- Eyes. Caterpillars have six small eyespots on each side of the head, while this creature has only one.
- Pro-legs. Caterpillars have up to four pairs of prolegs (the fleshy legs along the body, *not* including the front three pairs of true legs with claws). This creature has 7 pairs that I can see, including the back end.
- Behavior. Whenever it is touched by anything, it thrashes around wildly.

It could only be one thing - a sawfly larvae!
Sawflies are in the order Hymenoptera along with the ants, bees, and wasps. There are several sawfly families - I'm not yet sure which family this larvae belongs to.