There are a couple of ways to deal with the caterpillars. One method is to rotate using some biological controls, I use something called Safers Caterpillar Spray, which is a concoction of
Bacillus thuringiensis bacteria. These bacteria, when ingested by the caterpillar, give it an awful stomach ache and kill it. The other product is Monterey Garden Spray with
Spinosad in it. You can also try tenting, but you'll have to be EXTREMELY diligent about keeping it closed at all times or you could end up with a huge population of pest species, with no way for beneficial/pest-eating species to get in and do their work.
Apply these preventative sprays every two weeks as soon as buds begin to form, the very first pistils.
Also, know that darker and more purple strains tend to get hit hardest, so you could try planting trap crops such as dark-colored Indian corns. I like to grow Indian corn varieties because I some family members who go gluten-free and heirloom corns are perfect. They make very ugly cornbread, but just one bite and you'll be a convert! Hooker's is a great corn for this, as it grows a bit taller, is fantastic to eat sweet (green, unripe), or can be left on the stalk to dry in situ for harvest later. Seeds are viable once dried, and can be parched or ground. Parching is a bit like popping except it doesn't pop.
