Predatory mites are adult mites that seek out and kill pest mites, particularly the common spider mite. They are shipped live, ready to seek and destroy pest populations. Control pests without the use of chemical pesticides and their harmful side effects and residue. Best used at the first sign of an infestation, you only need two-to-five adults per plant, or 500-to-2,000 per tree. Each container includes 2,000 live adults.