Spray coverage may influence the efficacy of insecticides targeting the invasive vinegar fly Drosophila suzukii (Matsumura), a primary pest of raspberries and blackberries. In commercially managed caneberries, spray coverage is typically lowest in the inner and lower plant canopy, regions that overlap with higher levels of adult D. suzukii activity. To understand how spray coverage of fruit impacts efficacy against D. suzukii, laboratory bioassays were conducted using raspberries. In laboratory bioassays, higher spray coverage did not impact larval infestation rates but did increase adult mortality, indicating that flies can avoid a lethal dose of insecticide when applications do not achieve adequate coverage. We also evaluated how carrier water volume impacts spray coverage patterns throughout the canopy of raspberry and blackberry plants using both airblast and CO2 backpack sprayers. Increasing carrier water volume generally improved spray coverage in the lower plant canopy. However, effects in the upper plant canopy were inconsistent and varied between sprayer types. In addition to carrier water volume, other approaches, including adjusting the pesticide sprayer equipment used and/or sprayer calibration, should also be explored to improve coverage. Growers should evaluate spray coverage in their caneberries to identify and troubleshoot coverage issues. Results from this study indicate that taking the time to optimize this aspect of pesticide application may improve chemical management of D. suzukii and will likely also improve control of other important caneberry pests.

中文翻译：

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在多样化的水果农场优化铃木果蝇（双翅目：果蝇科）管理的甘蔗浆果喷雾覆盖率

喷雾覆盖可能会影响针对侵入性醋蝇 Drosophila suzukii (Matsumura)（覆盆子和黑莓的主要害虫）的杀虫剂的功效。在商业管理的甘蔗中，内部和下部植物冠层的喷雾覆盖率通常最低，这些区域与较高水平的 D. suzukii 活动重叠。为了了解水果的喷雾覆盖如何影响对 D. suzukii 的功效，使用覆盆子进行了实验室生物测定。在实验室生物测定中，更高的喷洒覆盖率不会影响幼虫的侵染率，但确实会增加成虫的死亡率，这表明当应用未达到足够的覆盖率时，苍蝇可以避免使用致死剂量的杀虫剂。我们还使用鼓风和 CO2 背负式喷雾器评估了载水量如何影响整个覆盆子和黑莓植物冠层的喷雾覆盖模式。增加载水量通常会改善下部植物冠层的喷雾覆盖率。然而，上部植物冠层的影响是不一致的，并且因喷雾器类型而异。除了载水量外，还应探索其他方法，包括调整使用的农药喷雾器设备和/或喷雾器校准，以提高覆盖率。种植者应评估其甘蔗的喷雾覆盖率，以识别和解决覆盖率问题。这项研究的结果表明，花时间优化农药施用的这一方面可能会改善 D.