How to get rid of caterpillars

[CJBUBBER]

I have Jacobs Ladders growing in my garden and every year they get eating by caterpillars. They start off like tiny little maggots and ever leaf has hundreds on them, then they turn into big fat caterpillars after feasting on my plants. I spray them with insectercide which gets rid of them short term, then they come back. Every year is the same. Does enyone know how to get rid of them once and for all

[Robinia]

I have Jacobs ladder & have never had a problem & from what you describe I'm wondering if your plants are Solomon's seal
here?

what you describe sounds like sawfly lavae (not caterpillars) which can only be controlled by picking them off & killing them as they become visible (ugh! I know!) or using a contact insecticide.
I don't use chemicals but I usually manage to hold on to my solomon's seal for a short while & enjoy it until the larvae start going faster than I do (not difficult).

If I'm wrong about your plant please ignore this.... :o)

[CJBUBBER]

Thanks Robinia, you are right, the plants in question are Solomon's seal, but it would be impossible to pick off these bugs because there are thousands of them and they really are much faster than me!!! Any other suggestions?