Generation-dependent demography and predation capacity of Amblyseius swirskii (Acari: Phytoseiidae) fed on saffron pollen

ABSTRACT Using alternative food for mass rearing of phytoseiid predatory mites may facilitate their cost-effective production. Demographic parameters of Amblyseius swirskii Athias-Henriot fed on saffron (Crocus sativus) pollen was determined over 20 continuous generations. Furthermore, the ability of A. swirskii to consume the natural prey Tetranychus urticae Koch after the first, 10th and 20th generations was evaluated. The longest (7.40 d) and shortest (6.18 d) development time occurred in the first and 10th generations, respectively. Females at the 10th generation laid their eggs earlier (after 2.63 days) and also had higher fecundity (49.46 eggs) compared with other generations. The gross reproductive rate (GRR), net reproductive rate (R 0), intrinsic rate of increase (r) and finite rate of increase (λ) of A. swirskii remained stable during different generations. Furthermore, the results of this study revealed that the values of r, GRR and λ were not significantly affected by the generation. The net predation rate (C 0), and finite predation rate (ω) of this predator in 20th generation was significantly higher than the first and 10th generations, which represents high predation capability of the predator after rearing on pollen for a long time. Finally, it can be concluded that saffron pollen maintained a proper performance of A. swirskii up to 20 generations and this alternative diet can be used for mass rearing of this predatory mite.