Predatory mites are slightly larger than pest mites and are an effective control on two-spotted spider mite and thrips. They have a quick reproductive period and can control infestations within a week if they are present in high enough numbers.
How to attract predatory mites
The most effective way to utilize predatory mites as a biological control is to release them into your garden or greenhouse when a spider mite or thrip infestation is occurring. In the presence of a food source (spider mites or thrips) the predatory mites will feed a reproduce quickly until the infestation is under control.
You can purchase predatory mites online from Arbico here:
Spider mites and thrips
Predatory Mite (photo credit)