Comparing chemical and biological control strategies for twospotted spider mites (Acari: Tetranychidae) in commercial greenhouse production of bedding plants.
J Econ Entomol
; 102(1): 336-46, 2009 Feb.
Article
em En
| MEDLINE
| ID: mdl-19253653
ABSTRACT
Efficacy, costs, and impact on crop salability of various biological and chemical control strategies for Tetranychus urticae Koch (Acari Tetranychidae) were evaluated on mixed plantings of impatiens, Impatiens wallerana Hook.f (Ericales Balsaminaceae), and ivy geranium, Pelargonium peltatum (1.) L'Hér. Ex Aiton (Geraniales Geraniaceae), cultivars in commercial greenhouses. Chemical control consisting of the miticide bifenazate (Floramite) was compared with two biological control strategies using the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari Phytoseiidae). Treatments were 1) a single, early application of bifenazate; 2) a single, early release of predatory mites at a 14 predatorpest ratio based on leaf samples to estimate pest density; 3) a weekly release of predatory mites at numbers based on the area covered by the crop; and 4) an untreated control. T. urticae populations were monitored for 3 wk after the earliest treatment. When plants were ready for market, their salability was estimated. Bifenazate and density-based P. persimilis treatments effectively reduced T. urticae numbers starting 1 wk after plants had been treated, whereas the scheduled, area-based P. persimilis treatment had little or no effect. The percentage of flats that could be sold at the highest market wholesale price ranged from 15 to 33%, 44 to 86%, 84 to 95%, and 92 to 100%, in the control, weekly area-based P. persimilis, bifenazate, and single density-based P. persimilis treatments, respectively. We have shown that in commercial greenhouse production of herbaceous ornamental bedding plants, estimating pest density to determine the appropriate number of predators to release is as effective and offers nearly the same economic benefit as prophylactic use of pesticides.
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Base de dados:
MEDLINE
Assunto principal:
Carbamatos
/
Controle Biológico de Vetores
/
Tetranychidae
/
Hidrazinas
/
Inseticidas
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article