Survival time and size of Neoseiulus californicus (Mesostigmata: Phytoseiidae) reared on different prey species and prey life stages

Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) is among the most commonly used predatory mites in biological control programs. Tetranychus urticae Koch (Trombidiformes: Tetranychidae) and Polyphagotarsonemus latus (Banks) (Trombidiformes: Tarsonemidae) are the important pest mite species in many agricultural crops worldwide. In the present study, the effect of diet (varying in prey species, prey stage) on the future starvation tolerance and body size at maturity of N. californicus were investigated. The diets used for N. californicus were the mixed stages of P. latus, mixed stages of T. urticae, T. urticae eggs and T. urticae actives (larvae, protonyph and deutonymph). 1-2-day-old mated adult females were held without food and water at 25 +/- 1 degrees C, 65 +/- 5% relative humidity and 16:8 h light/dark photoperiod. The survival times of predators were recorded twice a day at 12-h intervals until they died. The dorsal shield lengths and widths of N. californicus females reared on the four different diets were separately measured. The results confirm that the starvation time and dorsal shield size of N. californicus females were influenced by diet type. The N. californicus females reared on active only or eggs only of T. urticae lived longer under no-food and no-water conditions than those of females reared on the mixed stages of T. urticae only or P. latus only. They were also longer than those females on the mixed stages of T. urticae only or P. latus only. Additionally, the females on T. urticae mixed stages only were larger than those of females on P. latus mixed stages only.