Grasshopper, caterpillar, bee/wasps ....... others, - a lot of possibilities depend on where you live. You might consider adding that info to you're visible user info - like my z5b-6a mid-MI. It will help others to offer more specific advice and get a better feel for your situation/conditions. Al

I don't believe it to be a caterpillar at all. They look more like the larvae/pupae of a beetle...maybe a Colorado potato beetle? I wouldn't wait around for an ID, though. Yikes! Rather than experiment with a home made brew, I'd strongly suggest a spray of insecticidal soap directly on these little pests. Jean...what do you think these might be?

I don't know where you're at, but I'm in Southwest Michigan and I'm in the midst of an earwig infestation. I couldn't figure out what was defoliating my plants until I went out last night and saw SWARMS of them on my plants. I have some photos of the damage in the link below. Here is a link that might be useful: Attack of the earwigs

FWIW, there are teeny tiny snails here that do that kind of damage. I use the iron phosphate type bait & sprinkle it around newly seeded areas & plants they seem to prefer. Culprit also may be tiny caterpillars that either drop to the ground or blend in to the undersides of the leaves - hiding along the veins & exactly the same color as their food. I scout those carefully & squish. Some Bt can help as well. Luckily, the damage doesn't appear too severe, plants may just outgrow it...