Predator mites (Acarina: Hypoaspidae) are fabulous wee beasties. I got some off a friend who orders them straight from the "lab". They come in "vials" of 500, 1000, 2000 or whatever else you require.
I bought them when I recieved a Brachypela auratum with a major mite infestation, something I would have NEVER seen without the aid of my macro lens. Now when it comes to treating mites on an arachnid you are limited as to what you can do. You can't use anything chemical near them. My only option was predator mites and a bit of common sense (ie quarantine, drying out the enclosure etc).
You may be thinking it's madness to introduce mites into an animals inclosure that is already covered in the wee buggers HOWEVER hypoaspis mites do not attack the host. They prey on the real pests as their only food source. Once the mites, eggs and larve are eaten up, the predators start to die off.
I used approx half a "spoonfull" of predator mites and shook them over the substrate of the T's enclosure. This was approximatley 3 weeks ago. I have been taking regular macro shots of the spider to check on the areas most affected by the insect mites and sure enough the numbers are dwindling. I am going to change the whole enclosure again in about a week to reintroduce a new batch of predator mites and to keep the enclosure dry (as the stupid spider keeps knocking her waterbowl all over the place and soaking the substrate which ensures pest mites have hot humid conditions which are perfect breeding grounds).
I will attempt to get some macro shots of the actual predator mites. They are like little soldiers on a mad mite muncing mission. I am sure they are making huge amounts of progress in eating away at the spider mites and I will continue to use them and recommend them to anyone. If I ever had to, I would deffinatley use them for snakes.
Any other questions, feel free to ask!