For me, instead of growing insects for food, I'd rather attract insects to the plant. What I have done was to put a banana peel near my droseras for example, which attracts fruitflies, and they usually end up on the drosera leaves as food.
The only thing that I grow for my CPs, are moina/Daphnias for my utricularia and Aldrovanda, but actually the main purpose for that culture is for my fish collection, I don't feed my water CPs daphnias that often.
TTFN
Arvin