What I am thinking about trying for my squash bug problem, but haven't yet is Neem oil.
It has two methods of killing - like any oil it can kill on contact, by clogging up the insect's breathing pores. So you want to be careful to spray late in the day after the honeybees have gone home. Otherwise, once it is on the leaves, it kills when ingested by leaf eaters and is harmless to non-leaf eating insects.
It is a bit slow acting. It works sort of as a hormone disrupter, messes up the bug's system so they quit eating, breeding etc and eventually die. So you won't see them falling over dead instantly, but it should work.