A candidate of predatory phytoseiid mites (Acari: Phytoseiidae) for the control of the European red mite, Panonychus ulmi (Koch), (Acari: Tetranychidae) in Japanese apple orchards

Apple (Malus domestica Borkh.) trees that had not been sprayed with either insecticides or miticides were explored for the occurrence of tetranychid and phytoseiid mites, and predatory characteristics of the phytoseiid mites were investigated in the laboratory at 20+/-0.5degreesC, with a 15L:9D photoperiod and 90+/-5% RH, to find an appropriate domestic phytoseiid predator for controlling Panonychus ulmi (Koch) in Japan. Amblyseius womersleyi Schicha, Amblyeseius tsugawai Ehara and Typhlodromus vulgaris Ehara were found on apple trees inhabiting P. ulmi and Tetranychus urticae Koch. Among phytoseiid mites sampled, T. vulgaris showed a favorable developmental ratio of 75% with the female ratio of 67%, when reared on P. ulmi. Mated females of T. vulgaris laid eggs when fed larvae and adults of P. ulmi. On the contrary, immature stages of T. vulgaris neither consumed prey nor developed, and mated females reared on P. ulmi laid no eggs when fed T. urticae. Therefore, T. vulgaris was expected to be an effective predator for suppressing the P. ulmi population in apple orchards under reduced spray programs.