I think that buying spikes is the best idea for most folks who want to feed BBs, they are full grown maggots ready to turn into pupae, so you don't have to feed them. A very few people, Carey and I are the only two I know off had, grow their own, but it is not for the squeamish and most folks have trouble the first time they try and end up stinking out the house and enraging significant others. Fortunately, my only SO is Tucker, and he doesn't get a vote.
If you are interested in trying to start a fly culture in a 12" cube, talk to Carey who has, I think, a care sheet, and sells the medium. If you put "kova" into the search engine, you should come up with some of mine.
Wasps can be captured by leaving a little jam in a jam jar with some small holes -- large enough for them to crawl into the jar but not large enough for them to fly out. They do not respond well to chilling, though, so be careful. There is no need to remove the stinger, though, fortunately. Large mantids will catch them in nature, as the French naturalist Farbre has described, without any harm.
If honey bees are abundant in your area, they are an excellent natural food because in addition to animal protein, they also carry more pollen than most insects. You can catch them, and wasps, in a medicine jar. Be aware, though, that Rick has a strong emotional objection to feeding honey bees to mantids ( he cites CCD, but obviously the capture of a few bees in any given area won't affect that one way or the other) and, as a forum correspondent recently pointed out, isn't above silently deleting references to this subject,
