title: Predatory mites double the economic injury level ofFrankliniella occidentalisin strawberry.
abstract: The western flower thripsFrankliniella occidentalis(Pergande) (Thysanoptera: Thripidae) causes bronzing to strawberry fruit. Management of insecticide-resistant strains relies on the integration of predators with carefully timed use of the few insecticides available. Effective management requires better understanding of economic injury levels (EILs) and the factors that affect them. The densities ofF. occidentalisand the predatory miteNeoseiulus cucumeris(Oudemans) (Acari: Phytoseiidae) were manipulated in field experiments. All stages of flower and fruit were susceptible to thrips damage, but larvae caused nearly twice as much damage as adults per individual. The EIL was about four adult thrips per flower in the absence of predators, but increased to over eight at densities ofN. cucumeristypical of good establishment in crops. The EIL could be increased by about 0.7 adult thrips per flower for everyN. cucumerisper flower. The results were supported by measurements of EILs in commercial crops.
authors.affiliation: Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle Under Lyme, Staffordshire ST5 5BG UK.
authors.forename: Clare
authors.initials: C
authors.lastname: Sampson
authors.affiliation: Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle Under Lyme, Staffordshire ST5 5BG UK.
authors.forename: William D J
authors.initials: WD
authors.lastname: Kirk
keywords: Acari; Economic injury level; IPM; Neoseiulus cucumeris; Phytoseiidae; Thripidae; Thysanoptera; Western flower thrips