Single versus multiple releases of predatory mites combined with spinosad for the management of western flower thrips in strawberry

Authors

Touhidur Rahman, Department of Agriculture and Food, WAFollow
Helen Spafford, Department of Agriculture and Food, WAFollow
Sonya Broughton, Department of Agriculture and Food, WAFollow

Document Type

Article

Publication Date

12-30-2010

Journal Title

Crop Protection

ISSN

Print: 0261-2194

Keywords

Frankliniella occidentalis, Typhlodromips montdorensis, Neoseiulus cucumeris, Hypoaspis miles, Spinosad, Single species releases, Multiple species releases, Strawberry

Disciplines

Biosecurity | Fruit Science | Horticulture

Abstract

Western flower thrips, Frankliniella occidentalis (Pergande), is a major pest of strawberry and other horticultural and ornamental crops. Biological control of F. occidentalis with predatory mites is recommended as an additional management strategy to chemical control in glasshouse and protected crops. However, it is not known whether multiple (two or three) species releases of predatory mites are more effective than single species releases. The effect of an application of spinosad followed by mite releases could further increase suppression of F. occidentalis. In a series of trials in the glasshouse, we evaluated three commercially available predatory mite species, Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) and Hypoaspis miles (Berlese). Strawberry plants were sprayed once with either spinosad at the recommended rate or with water. F. occidentalis adults were released onto plants 24 h after spraying, and mites were released six days later. Spinosad significantly reduced F. occidentalis compared to the control (water). T. montdorensis, N. cucumeris and H. miles significantly reduced F. occidentalis compared to the ‘no mite’ treatment. Spinosad had no effect on T. montdorensis and N. cucumeris, as their numbers did not differ between the spinosad and control treatments; H. miles was not recovered. When mites were released after an application of spinosad, greater suppression of F. occidentalis was achieved than with releases of predatory mites alone. When released as a double species combination, ‘T. montdorensis and H. miles’ was the most effective combination. There was no difference in efficacy between releases of ‘T. montdorensis and H. miles’ or ‘T. montdorensis, N. cucumeris and H. miles’. We conclude that multiple species releases are more effective than single species releases, and that biological control of F. occidentalis with predatory mites can be used together with spinosad.

Recommended Citation

Rahman, T, Spafford, H, and Broughton, S. (2010), Single versus multiple releases of predatory mites combined with spinosad for the management of western flower thrips in strawberry. Crop Protection, 30 (4), 468-475.
https://library.dpird.wa.gov.au/bs_research/119