title: Testing for non-target effects of spinosad on twospotted spider mites and their predator Phytoseiulus persimilis under greenhouse conditions.
abstract: The compatibility of the selective insecticide spinosad (Conserve SC), at rates recommended for thrips control in greenhouses, with release of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) to control spider mites, was investigated in a crop of ivy geranium Pelargonium peltatum, cultivar 'Amethyst 96.' Plants were inoculated with twospotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), 2 weeks before treatments were applied. There were three treatment variables, each at two levels: predators (released or not), spray application (water or Conserve SC at 2 ml/3.79 l), and timing of spray (1 day before or after predators were released). Twospotted spider mite populations then were sampled twice each week over a three-week period. The application or timing of spinosad had no effect on the ability of the predator to reduce the population of spider mites. Spider mite populations in the no-predator treatment continued to expand over the course of the experiment, while those in the predator-release treatment declined. We conclude that P. persimilis can be used in conjunction with spinosad on ivy geraniums without causing obvious detrimental effects to this predator or leading to a reduction in biological control.
authors.affiliation: Department of Entomology, Kansas State University, 123 West Waters Hall, Manhattan, KS 66506, USA.
authors.forename: Kiffnie M
authors.initials: KM
authors.lastname: Holt
authors.forename: George P
authors.initials: GP
authors.lastname: Opit
authors.forename: James R
authors.initials: JR
authors.lastname: Nechols
authors.forename: David C
authors.initials: DC
authors.lastname: Margolies
mesh_terms: D000818:Animals; D004338:Drug Combinations; D005260:Female; D031315:Geranium / Q000469:parasitology*; D007306:Insecticides; D018942:Macrolides; D008924:Mite Infestations / Q000517:prevention & control; D010572:Pest Control, Biological / Q000379:methods* / Q000592:standards; D011897:Random Allocation; D040102:Tetranychidae / Q000254:growth & development*
chemical_list: D004338:Drug Combinations; D007306:Insecticides; D018942:Macrolides; C415329:spinosad