This is probably tobacco budworm. There is a relatively new product on the market, made from byproducts during a fermentation process with some very specific microorganisms.
It has found to have a very toxic effect on many pests which are caterpillars, exactly what you are talking about, while safe for most beneficial insects like ladybugs and green lacewings. It is in a liquid form and can be sprayed. The ingredient is called spinosad (pronounced spine o sid).
There may different trade names on labels so you have to look at the ingredients to find it or talk to a knowledgeable person in the store. I doubt if it is in the hardware stores but should be in the nurseries.
By Robert Morris