NY006 - Improved Strains for Integrated Mite Control

The predatory mite Phytoseiulus persimilis has been used extensively overseas and in Australia as a major component in integrated pest mite control (IMC) programs, targeted primarily are twospotted mite, Tetranychus urticae, a major horticultural pest. Two identified limits to further the success of IMC were the limited tolerance of P. persimilis to pesticides; in particular organophosphates and synthetic pyrethoids, and poor performance under high temperature and lower humidity conditions often experienced in Australian productions houses. The aims of the project were to survey and select field strains of P. persimilis on the basis of their tolerance to the organophosphate dimethoate and high temperatures (>39⁰C and <80% RH). Whilst not developing more tolerant strains with high efficacy, the investigations provided useful information to improve effectiveness of P. persimilis in the field and will assist in quality assurance of other mass-reared beneficial arthropods.