Small Green Caterpillars on Kale Leaves - Answered

I've been trying to figure out what's eating my Tuscan kale.  I took the time to examine the leaves very, very closely, and found the culprit.  Tiny green caterpillars.  Before I squished them to death, I took a couple of pictures.

After I squished them, I applied Bt to the kale plants as well as the neighboring broccoli.  Hopefully that will do the trick.

I am curious what type of caterpillars they are - i.e. what type of larvae these would become if I had allowed them to live.


ANSWER

It's a little hard to tell considering they are so small. I would guess a cabbage looper. But Bt should probably help whatever kind it is. When they move, does their abdomen curl up towards their "chest," making a loop? Like this:

 

They will turn into a moth, which means that you probably won't see the adult too much. When you find these, they sometimes get into the heads of lettuce or brussels sprouts. When a plant is established and healthy, they often don't do enough damage to warrant a treatment, but they can cause problems in young plants. And the damage isn't very pretty, as they are chewing holes in your pretty leaves.

Regardless, the Bt should help, along with squishing them!