author(s)
Maryam Rezaie, Alireza Saboori, Valiollah Baniamerie and Ali Hosseini-Gharalari

abstract
Neoseiulus californicus (Acari: Phytoseiidae) is an effective predator of spider mites. The prey-stage preference of N. californicus was studied on different developmental stages of Tetranychus urticae on seven strawberry commercial cultivars (‘Aliso’, ‘Chandler’, ‘Camerosa’, ‘Gavita’, ‘Sequia’, ‘Marak’ and ‘Yalova’). Functional response of adult female of N. californicus to egg and protonymph of T. urticae was determined. Experiments were carried out on strawberry leaflets in Petri dishes in the laboratory. The protonymph and deutonymph of N. californicus preferred T. urticae eggs to protonymph. However, the female predatory mite preferred protonymph T. urticae. The preference index on different strawberry cultivars was not different. The functional response to egg of T. urticae on ‘Chandler’, ‘Gaviota’ and ‘Camarosa’ was type П, whereas it was type III on protonymph of T. urticae on ‘Sequia’, ‘Marak’, ‘Yalova’ and ‘Aliso’.The handling time are different among the cultivars (the highest value was reported for ‘Marak’ (1.06±0.035 hour) on egg of T. urticae, for ‘Yalova’ (1.45±0.05 hour) and for ‘Camerosa’ (1.44±0.13) on protonymph of T. urticae. The predation rate of different developmental stages of N. californicus on ‘Chandler’ was higher than the other cultivars (protonymph (2.6±0.3), deutonymph (3.8±0.2) and adult (9.5±0.6) in 24 hours) on egg of T. urticae, which might be due to least trichome or difference chemical and physical structure leaves. It is recommended to use this predatory mite to control different stages of T. urticae. However, the protonymph stage of T. urticae is the most suitable target stage.