Development, survival, and reproduction of Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) feeding on fresh versus frozen eggs of Tetranychus urticae Koch (Acari: Tetranychidae)

Phytoseiulus persimilis Athias-Henriot is an important biocontrol agent for controlling spider mites (Tetranychus spp). Rearing P. persimilis is relatively expensive due to the need to raise spider mites (e.g. Tetranychus urticae Koch), as prey, on live plants. Frozen eggs of T. urticae can be easily stored and used as a potential feed for laboratory rearing of P. persimilis. This study investigated the performance of frozen T. urticae eggs compared with fresh eggs as food for rearing P. persimilis. Under laboratory conditions, the survival, immature development, consumption, and oviposition of P. persimilis given frozen or fresh T. urticae eggs were observed. The influence of the dietary experience of P. persimilis females (i.e. fed on frozen or fresh spider mite eggs) on offspring's development and consumption was also examined. The survival and development of P. persimilis were not affected by the different diets. However, individuals fed on frozen T. urticae eggs had a reduced oviposition rate and an increased consumption compared with those given fresh eggs. The maternal dietary experience did not affect the development and consumption of P. persimilis. As the nutritional quality of T. urticae eggs is likely reduced during freezing, the frozen eggs of T. urticae may be inadequate compared with fresh eggs in rearing P. persimilis. Nevertheless, frozen eggs have the potential as supplementary food for P. persimilis. Future studies can investigate the performance of frozen T. urticae eggs on the lifespan and lifetime fecundity and in maintaining a population of P. persimilis in the field.