The influence of sublethal deposits of agricultural mineral oil on the functional and numerical responses of Phytoseiulus persimilis (Acari: Phytoseiidae) to its prey, Tetranychus urticae (Acari: Tetranychidae).

Occasional pesticide application in integrated pest management to at least part of a crop requires that any biological control agents must re-invade previously sprayed areas in order that resurgent pests can be constrained. The ability of the phytoseiid predatory mite Phytoseiulus persimilis to feed on adult two-spotted spider mite (TSSM) Tetranychus urticae on excised leaf discs in both control conditions and in a treatment with a sub lethal residue of agricultural mineral oil (AMO) was assessed. The predator exhibited a Type II functional response with the asymptote significantly higher in the AMO conditions due to the fact that the prey grew slower and reached a smaller size in this treatment.