Biorational Pesticides for the Control of Brevipalpus yothersi (Acari:Tenuipalpidae) and their Compatibility with Predatory Mites

Recently, several plant viruses transmitted by Brevipalpus mites were found infecting ornamental plants in urban and unmanaged landscapes. The main purpose of this research was to identify suitable tools for managing Brevipalpus yothersi in these environments by evaluating the efficacy, persistence, and rainfastness of selected biorational pesticides, as well as their compatibility with the predatory mite Amblyseius largoensis. We found that horticultural oils (i.e., petroleum distillates with varying levels of refinement, marketed as mineral or paraffinic oils) and Beauveria bassiana (Strain GHA) suppressed all developmental stages of B. yothersi at levels comparable to spirodiclofen, a commonly used acaricide for controlling B. yothersi. The paraffinic oil provided the best overall performance across the rainfastness, residuality, and greenhouse evaluations. This food-grade horticultural oil is exempt from residue tolerances and could be readily adopted for B. yothersi control in urban landscapes. Paraffinic oil had adverse effects on predatory mites. However, predator populations recovered after paraffinic oil application, and the combined treatment of paraffinic oil + A. largoensis ultimately provided better control than either the predators or the oil alone. When properly applied, horticultural oils provide a practical option for controlling populations of viruliferous Brevipalpus mites in urban and unmanaged landscapes.

近期，研究人员在城市景观带及自然无人管护区域中发现多种由短须螨属螨类（Brevipalpus mites）传播的植物病毒侵染观赏植物。本研究的核心目标是，通过评估筛选出的生物源农药（biorational pesticides）的防效、持效性与耐雨水冲刷性能，以及其与捕食螨拉戈钝绥螨（Amblyseius largoensis）的相容性，筛选适用于该环境下约特短须螨（Brevipalpus yothersi）防治的有效手段。研究发现，园艺用油（horticultural oils，即不同精炼程度的石油馏分，商品名为矿物油或石蜡油）与球孢白僵菌（Beauveria bassiana，菌株GHA）对约特短须螨各发育阶段的抑制效果，可与常用于防治该螨的螺螨酯（spirodiclofen）这一常用杀螨剂相媲美。石蜡油在耐雨水冲刷性、残留活性及温室盆栽试验中综合表现最优。该食品级园艺用油不受残留限量规定限制，可快速推广应用于城市景观带内约特短须螨的防治工作。石蜡油对捕食螨存在一定不利影响，但施药后捕食螨种群可自行恢复；且石蜡油与拉戈钝绥螨联合施用的处理方案，最终防治效果优于单独使用捕食螨或单独施用石蜡油的处理。若施用方式得当，园艺用油可作为城市景观带及无人管护区域内带毒短须螨种群防治的实用方案。