I just came from my garden. It seems I had the same problem on my broccoli.
Green caterpillars all over each one. I just wasn't looking close enough to see
them before. They were very hard to see because of their color. But the damage
they caused was a sure sign something was there. I have about 20 plants. I just
squished each and every one of those nasty bugs and now the problem is gone. No
poison.

Jack