Growing them captive works, but I think the trick is that all feed for anything edible such as grasshoppers, Locusts, snails,etc has to be organic since like shellfish they do concentrate toxins in their fatty organs. I recall that grasshoppers which are a delicacy in Mexico, was a big source of lead contamination in children and adults. I'm not real sure that captive insect farms for consumption, would be the answer. Farmed seafood is a hit or miss regarding contaminants that are ingested while being fed. If I am going to feast on insects which isn't really that far fetched since I eat crustaceans and escargot, I want them organic, free range with a hint of garlic.