Difficult for me to answer because any pests, not to mention pest treatments, will be different there than here in the UK. Perhaps you could go to your nearest garden centre and have a look at the pesticide section to see what's available, and even ask the staff there what would be best.

Thanks I just found the name of the plant - will do!

My favorite for that caterpillar is spinosad, though B. t. makes a good preventative.