A great many mites in the family Phytoseiidae are predators of spider mites. In addition to those that occur naturally, some of these are produced in commercial insectaries for release as biological controls. Among those most commonly sold via mail order are Galendromus occidentalis , Phytoseiulus persimilis , Mesoseiulus longipes and Neoseiulus californicus . Although these have been successful in control of spider mites on interior plants, effective use outdoors has not been demonstrated in Colorado. Predatory mites often have fairly high requirements for humidity, which can be limiting.
Most suppliers provide information regarding use of the predator mites that they carry.
One reason that spider mites become problems in yards and gardens is the use of insecticides that destroy their natural enemies. Malathion can aggravate some spider mite problems, despite being advertised frequently as effective for mite control. Water Management Adequate watering of plants during dry conditions can limit the importance of drought stress on spider mite outbreaks. Periodic hosing of plants with a forceful jet of water can physically remove and kill many mites, as well as remove the dust that collects on foliage and interferes with mite predators. Disruption of the webbing also may delay egg laying until new webbing is produced.