[Pumilo]

I would imagine fruits could pretty easily bring mites in. In my vivs, however, the springtails love grapes.

I have been experimenting with some different mixes and have had a lot of success by dampening a mushroom slice then dipping it into some yeast so that the yeast sticks to it then feeding those to the springtails. I have also tried rice and did fine but the mushroom and yeast thing seems to be the fastest producer for me.
I am interested in trying the grapes now though. Maybe a yeast powder crusted grape slice? (Kind of like a powdered donut for springtails. )

I mentioned grapes but I don't recommend grapes in a springtail culture. I think that they would easily bring mites in. Every viv, however, gets mites once it has been set up long enough. That is why I mentioned grapes within your viv. It works as a feeding station for your flies and doubles as springtail food.

 

[Percularis]

WOW!!

Three days after adding a few pinches of active bakers yeast I checked my springtail culture. They were literally just finished it up. There were HUNDREDS crawling all over the feeding area! They go crazy over this stuff!

 

[Pumilo]

Glad it's working for you. You can get a huge, 2 lb bag at Costco for about $3 or $4.