Phytoseiid mites were first studied from an economic standpoint by Parrott et al. (1906), who described the value of Seius pomi Koch in controlling the pear leaf blister mite Eriophyes pyri (Pgst.). The taxonomic and biological studies of Garman (1948), Nesbitt (1951), and Chant ( 1959) stimulated additional interest in phytoseiids as predators, and in recent years they have been studied rather extensively as biological control agents of phytophagous mites.