Try to find some more and hand pick them. Then, go with a couple weekly treatments of BT K variant. After that, bi-weekly. Should clear up the problem in no time. Available at ANY nursery/garden center. Goes by the names of Thuricide, Caterpillar Killer et al. Totally safe and organic.

Looks like cabbage looper caterpillars.

Kevin

I don't know if cabbage loopers like Artichokes, but they would certainly go for Brussels Sprouts, Pak Choi and Chinese Cabbage. There are a variety of caterpillars that eat artichokes and members of the cabbage family. Kevin's advice on Bt above remains valid for all of them. Especially when the caterpillars are young.

I usually don't worry much about Painted Lady caterpillars (as on artichokes). They are typically found at the base of a leaf, under a web. The damage you have looks like it came from something else.

There are some big grasshoppers out now, too. They could cause damage like that seen on your artichoke. Bt won't work on them.

I caught the caterpillar in the act. I think he would have eaten the entire leaf if I didn't stop him. Nasty little thing.

I'll be on the lookout for grasshoppers though.

A similiar catapillar ate on my squash and eggplant leaves/blossoms for a month. I finally applied malathion spray and killed em all! I rather stay organic, but they got out of hand.