Shrewsbury Paula M, Hardin Mark R
Department of Entomology, University of Maryland, College Park, MD 20742-4454, USA.
J Econ Entomol. 2003 Dec;96(6):1675-84. doi: 10.1093/jee/96.6.1675.
A laboratory trial evaluated four phytoseiid species for their potential as biological control agents of spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae). An augmentative biological control approach, using the predatory mites Neoseiulus fallacis Garman and Galendromus occidentalis Nesbitt (Acari: Phytoseiidae), was evaluated for reducing pest mite densities and injury, and economic costs on Juniperus chinensis 'Sargentii' A. Henry (Cupressaceae) in an outdoor nursery. Sequential releases of predator species, individually and in combination, were tested and compared with two commonly used miticides, a low-toxicity miticide, horticultural oil, and a conventional miticide, hexythiazox. Timing of treatments was based on grower-determined need, and predator release rates were based on guidelines in literature received from producers of beneficial organisms. Predator releases were more expensive and provided less effective suppression of spruce spider mites, resulting in greater spider mite injury to plants, compared with conventional pesticides. However, spider mite damage to plants did not differ in an economically meaningful way between treatments. Unsatisfactory levels of control seem related to under estimations of actual spider mite abundance based on grower perceptions and the beat sampling technique used to estimate predator release rates. These data suggest that when initial populations of spruce spider mite are high, it is unlikely that sequential releases of predator species, individually or in combination, will suppress spider mite populations. In this trial, augmentative biological control control was 2.5-7 times more expensive than chemical controls.
一项实验室试验评估了四种植绥螨作为云杉叶螨（Oligonychus ununguis (Jacobi)，蜱螨亚纲：叶螨科）生物防治剂的潜力。在室外苗圃中，采用捕食螨新小绥螨（Neoseiulus fallacis Garman）和西方盲走螨（Galendromus occidentalis Nesbitt，蜱螨亚纲：植绥螨科）的增殖性生物防治方法，以降低害虫螨密度和危害以及对桧柏‘萨金特’（Juniperus chinensis 'Sargentii' A. Henry，柏科）的经济成本。对捕食螨物种单独和组合的连续释放进行了测试，并与两种常用杀螨剂进行比较，一种是低毒杀螨剂园艺油，另一种是传统杀螨剂噻螨酮。处理时间基于种植者确定的需求，捕食螨释放率基于从有益生物生产者处获得的文献指南。与传统农药相比，释放捕食螨成本更高，对云杉叶螨的抑制效果更差，导致植物受到的叶螨危害更大。然而，各处理间叶螨对植物的损害在经济意义上并无差异。控制效果不理想似乎与基于种植者认知和用于估计捕食螨释放率的拍打采样技术对实际叶螨数量的低估有关。这些数据表明，当云杉叶螨初始种群数量较高时，单独或组合连续释放捕食螨物种不太可能抑制叶螨种群。在该试验中，增殖性生物防治比化学防治贵2.5至7倍。
