The mites that exist in fruit fly cultures are harmless towards ants, and technically the flies too (except in rare cases) if only they didn't exhibit population explosions. Mites that might fall Into the outworld may only present themselves as problems if hygiene is an issue in the first place, and only through stress inducing means of crawling over ants in large numbers; not through parasitic tendencies.
Bugblade is merely diatomaceous earth marketed in overpriced amounts. DE is used under where cultures are kept and as a barrier. It kills purely through mechanical damage, and if used properly ants should never come into contact with it in the first place.
To prevent spread of mites between cultures, both DE and mite paper is effective, though the latter is easier to use. The most important step that could prevent most of the trouble is to source mite free cultures in the first place, and then use proper sanitation and quarantine methods thereafter.
Edited by 123LordOfAnts123, June 13 2017 - 1:39 PM.