About once a week or so I've been finding a leaf or two on a tomato plant that has been mostly or completely skeletonized. The underside of the leaf is covered with a swarm of very small green caterpillars. Google hasn't been too helpful in identifying these guys so I'm not sure what they are or how to prevent them. I've been removing the leaves and destroying the caterpillars. One tomato plant in particular is usually the one affected. I'm not sure how large they'll grow vs their current size, so it could be a much larger pest that I just happen to catch early.

I've also noticed them (unless it was something else extremely similar) on a Zucchini leaf. In the case of the zucchini, I found them very early. There were to white fuzzy patches under the leaves. The caterpillars (much smaller this time) were contained within the fuzz & starting to work themselves out. So far no new sightings on the zucchini, though the tomato had them again today.

Any help identifying and treating would be REALLY appreciated! Thanks!