University of California Cooperative Extension, Kern County, Bakersfield, CA.
J Econ Entomol. 2021 Feb 9;114(1):415-423. doi: 10.1093/jee/toaa283.
Changes in almond production practices have caused sixspotted thrips, Scolothrips sexmaculatus Pergande, and the coccinellid beetle, Stethorus punctum LeConte, to replace phytoseiid mites as the dominant predators of spider mites in California almonds. We conducted a series of field studies to evaluate nine commercially available adhesive traps for S. sexmaculatus and S. punctum and found that the yellow strip trap was the most effective, least expensive, and easy to use. At peak population levels, individual cards routinely caught >1,000 S. sexmaculatus and >100 S. punctum trap-1 week-1. We documented that larger traps collected more S. sexmaculatus, and more S. sexmaculatus per square area, suggesting that the trap surface was attractive. We determined the number of traps needed to have 50, 70, and 90% confidence that the averages of trap captures were within 10, 30, and 50% of the population mean. Two yellow strip traps per orchard provided 90% confidence that trap captures were within 50% of the population mean if there were an average of 16.0 S. sexmaculatus trap-1 week-1 or 7.9 S. punctum trap-1 week-1. Populations required to attain the same levels of confidence using four traps per orchard were 3.9 S. sexmaculatus and 2.9 S. punctum trap-1 week-1. We conclude that use of the yellow strip trap to monitor for natural enemies, in combination with leaf samples for spider mites, has the potential to improve integrated pest management programs for spider mites, and assist future research to understand the biology and phenology of both predator species.
杏仁生产实践的变化导致六斑色蓟马（Scolothrips sexmaculatus Pergande）和食螨瓢虫（Stethorus punctum LeConte）取代植绥螨成为加利福尼亚杏仁中蜘蛛螨的主要捕食者。我们进行了一系列田间研究，以评估九种市售的粘性陷阱对 S. sexmaculatus 和 S. punctum 的效果，发现黄色条纹陷阱最有效、最便宜且易于使用。在种群高峰期，单个卡片通常每周捕获 >1000 只 S. sexmaculatus 和 >100 只 S. punctum 陷阱-1 只-1 周。我们记录到较大的陷阱收集到更多的 S. sexmaculatus，且每平方区域的 S. sexmaculatus 更多，表明陷阱表面具有吸引力。我们确定了需要多少个陷阱才能有 50%、70%和 90%的置信度，即陷阱捕获的平均值在种群平均值的 10%、30%和 50%以内。每个果园使用两个黄色条纹陷阱，如果每周平均有 16.0 只 S. sexmaculatus 或 7.9 只 S. punctum 陷阱-1 只-1 周，则有 90%的置信度可以保证陷阱捕获率在种群平均值的 50%以内。如果每个果园使用四个黄色条纹陷阱，则需要 3.9 只 S. sexmaculatus 和 2.9 只 S. punctum 陷阱-1 周-1，以达到相同置信水平。我们得出结论，使用黄色条纹陷阱监测天敌，并结合叶片样本监测蜘蛛螨，有可能改善蜘蛛螨的综合虫害管理计划，并有助于未来研究了解这两种捕食者的生物学和物候学。
