Opit George P, Perret Jamis, Holt Kiffnie, Nechols James R, Margolies David C, Williams Kimberly A
Department of Entomology, Kansas State University, Manhattan, KS 66506-4004, USA.
J Econ Entomol. 2009 Feb;102(1):336-46. doi: 10.1603/029.102.0144.
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 1:4 predator:pest 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.
在商业温室中，对凤仙花（Impatiens wallerana Hook.f，杜鹃花目：凤仙花科）和常春藤天竺葵（Pelargonium peltatum (L.) L'Hér. Ex Aiton，牻牛儿苗目：牻牛儿苗科）混栽品种上，评估了多种针对二斑叶螨（Tetranychus urticae Koch，蜱螨亚纲：叶螨科）的生物和化学防治策略的效果、成本以及对作物可销售性的影响。将杀螨剂联苯肼酯（Floramite）组成的化学防治与使用捕食螨智利小植绥螨（Phytoseiulus persimilis Athias-Henriot，蜱螨亚纲：植绥螨科）的两种生物防治策略进行了比较。处理方式包括：1）单次早期施用联苯肼酯；2）基于叶片样本估计害虫密度，以1:4的捕食者:害虫比例单次早期释放捕食螨；3）根据作物覆盖面积每周释放捕食螨；4）不进行处理的对照。在最早处理后3周内监测二斑叶螨种群数量。当植株准备上市时，评估其可销售性。联苯肼酯和基于密度的智利小植绥螨处理在处理植株1周后开始有效减少二斑叶螨数量，而按计划基于面积的智利小植绥螨处理几乎没有效果。在对照、每周基于面积的智利小植绥螨处理、联苯肼酯处理以及单次基于密度的智利小植绥螨处理中，能够以最高市场批发价出售的盆栽比例分别为15%至33%、44%至86%、84%至95%和92%至100%。我们已经表明，在商业温室草本观赏花坛植物生产中，估计害虫密度以确定释放捕食者的合适数量与预防性使用农药一样有效，并且提供几乎相同的经济效益。
