Personally....... Use whatever pesticide that doesn't kill bees and will do the job and meanwhile buy their cactus from the store until the bugs are GONE and the poison is degraded and gone. I don't really see any of these half measures getting rid of these miserable little pests.
There's the problem. How do I know when the pesticide is degraded and gone? When is it safe to feed the pads from my 40 stands of cactus? What do I do with the 100's of pounds of pads that are produced while the pesticide is still active and toxic? So many questions…
Are there pesticides, that will kill these things, but not kill bees? I'm not too worried about the bees because the bees have no reason to hang around my cactus stands, especially if they aren't flowering.