A new tray-type arena to mass rear Neoseiulus baraki, a predatory mite of coconut mite, Aceria guerreronis in the laboratory

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is an important predatory mite of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) and attempts are now being made to evaluate the effectiveness of augmenting N. baraki to control coconut mite in the field. These studies require a steady supply of N. baraki in large numbers. One major constraint of the existing method to mass rear N. baraki on Tyrophagus putrescentiae Shrank (Acari: Acaridae) in a closed arena without a water barrier was frequent contamination of cultures by other mites. This paper describes the development of an efficient method to mass rear N. baraki in the laboratory with less monitoring and relatively minimal contaminants. Three box-type arenas and a tray-type arena were tested to mass rear T. putrescentiae. Mites were successfully developed on two box-type arenas and the tray-type arena, but the production (2197 mites per tray in 4 weeks) of T. putrescentiae was significantly higher on the tray-type arena. A 110-fold increase of T. putrescentiae was achieved in tray-type arenas in 4 weeks. None of the box-type arenas could be maintained more than 5 weeks without acarine and fungal contaminations. N. baraki could be successfully reared on the tray-type arena at least for 6 weeks. More than 4800 mites per tray, a 240-fold increase was achieved in 5 weeks when T. putrescentiae was added at 3-week intervals. Advantages and disadvantages of the new method are described.