I recently had all my fruit fly cultures (around 10) and all my spring tail cultures (12) attacked by mites. It was terrible. I was fortunate that the mites didn't really like the super moist environment that the spring tails were in, so they slowly died out. The fruit fly cultures were a different story. <_< It took me 3 months to get rid of all mites in my fly cultures. I would constantly start new fly cultures when ever the mites would begin to build up (usually when the fly culture began to dry out). I also made sure to throughly wash the fruit fly culture containers with lots of soap (to kill the mites on the container). When finished washing, I would micro wave the container for 30-40 seconds to kill any remaining mites. Always making sure to sterilize my containers and start new cultures constantly slowly got rid of all the mites.