Likely caterpillars of one kind or another.

Don't know which specific ones are busy at your place, but the key is to look closely at top & underside of leaves.

At my place, the current bad guys on the cabbage family crops are these:

1. imported white butterfly (cats are up to 1 inch long, velvety green color helps them bled into the leaf.

2. diamondback moth -- very small cats, about 1/4 inch, also small pupal cases webbed to the leaf. These cats make "windows" (eat cells on surface, only) also holes.

Lots of possibilities: slugs, beetles, caterpillars, earwigs, etc. I suggest that you visit your garden after dark, with a flashlight, to see what you might find.

Didn't see your post, Jean. Not only are those Diamondback moth caterpillars small...but they're green! And they love cabbage, brocc., and cauliflower.

Yes, green. And *very* small! This is my first time, ever, to have them. And that on only 8 kohlrabi plants.

Thanks for all the tips folks. I did see some very, very small white flying bugs on the undersides of the leaves. Any idea what those might be?

Your description-very small white flying bugs on the underside of the leaves-suggests whitefly. Do a google search to see if they match up with what you've been observing and let us know.

Thanks for all the feedback. It appears I do have whitefly as well as small green catepillars eating the kale, cauliflower and broccoli leaves. I bought Thuricide to control the catepillars. Still researching how to organically control the whitelfies. Thanks again all!

My cauliflowers are in a screened lanai. I see no cats. but plenty of geckos. Could they be the culprits? Some of the leaves are eaten to the stem. Thanks