Biocontrol

Phytoseiulus persimilis is a highly successful biocontrol agent of plant-parasitic spider mites of the genus Tetranychus (Prostigmata: Tetranychidae). 

Over some 40 years, it has been commercially mass-reared for pest management programmes around the world, particularly against T. urticae (the two-spotted spider mite). 

Phytoseiulus persimilis is responsible for a reduction in the costs associated with pesticide use.

mostly used on 

  • crops grown under glass (food and ornamental plants), but also on some 
  • field grown ones.
  • infestations of plants in houses and offices

The specificity and voracity of its appetite for Tetranychus species means that prey is eventually eliminated from cultivated crops. Phytoseiulus persimilis is therefore reintroduced (augmentation) onto the crop in 

  • enormous numbers for rapid pest reduction (inundative release) 
  • small numbers at a critical point in the season (inoculative release). 

However, instances have been recorded of P. persimilis populations persisting and contributing to spider mite control without reintroductions, particularly when alternative hosts for the pests occur adjacent to the crop. 

The importance and versatility of this species has been increased by rearing strains that are resistant to pesticides, can complete their life cycle in wider temperature ranges and are adapted to additional host plants. (Helle and Sabelis, 1985; Kostiainen and Hoy, 1996; McMurtry and Croft, 1997; Zhang, 2003)