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?

looks like a katydid ;-) ... some sort of locust ?? ... not sure what the correct name is but we used to be fascinated with them as kids, finding their skeletons attached to trees every summer ...

Some of the symptoms you report had me worried because they can indicate a virus, but after seeing your pics, your plants just look really hungry and like they're suffering from drought stress. Many are probably very unhappy in the roots from overcrowding as well. There might be signs of fungal disease as well, but drought stress + nutrient deficiency can often look very similar. Note that nutrient deficiency can happen even if there's plenty of fertilizer if the roots are in bad condition and unable to take up the nutrients. I'm confused by this: - I fertilize once a week with tomato tone diluted according to the instructions on the bottle. as the only TomatoTone I know is granular. What exactly are you using? Also, are you checking moisture levels in the pots before watering, preferably using the old reliable stick-your-finger-down-in-the-soil method? Lastly, what are you growing them in? What is the medium in those containers?

you cant spray flower buds.. they usually die immediately .. do you actually have a bug problem that you are solving... or is your method all preventative ... are your sprays contact kill stuff .. but if there arent any bugs there.. then why are you spraying .... and being lazy .. and not looking it up.. do any of those products actually work on ants??? and as noted above.. NEVER spray anything on leaves in blistering sun ... you might blister or otherwise harm the leaves... sort of what your plants look like now ... be reactive in spraying.. not proactive.. imo ... and make sure the root bags stay out of direct sun .. you dont want hot roots ... creating watering problems .... though that may have nothing to do with all this ... lastly.. keep in mind.. Ts can get real ugly from mid summer on.. and still produce way too much ...lol... so dont be too worried about letting a few bugs get at them ... you need only react when the plant is threatened ... soon enough.. you wont have any friends left for all the Ts you will be trying to give away ... lol ken