Department of Horticulture, Oregon State University, Corvallis, OR 97331, USA.
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA.
J Econ Entomol. 2023 Jun 13;116(3):899-908. doi: 10.1093/jee/toad057.
Drosophila suzukii Matsumura (Diptera: Drosophilidae) is a key pest of soft-skinned fruit such as blackberry and blueberry. Differing seasonal spray regimes are expected to have variable effects on D. suzukii populations. Semi-field cage trials were performed at three locations in the United States (Georgia, Oregon, and North Carolina) on blueberry and blackberry crops to evaluate this hypothesis. Insecticides with different efficacy rates (ZC - zeta-cypermethrin, SPI - spinetoram, CYAN - cyantraniliprole) were applied during field experiments conducted within large cages. Treatment schedules consisted of two insecticide applications which performed over three weeks. Seasonal treatment schedules were applied in the following order: ZC-CYAN and CYAN-ZC in rabbiteye and highbush blueberry with the addition of a ZC-SPI treatment applied in blackberry. In addition, a population model was applied to simulate the relative efficacy of the insecticide schedules in Oregon on D. suzukii population model based on previously published efficacy, biological, and weather parameters. Overall, all schedules resulted in reduced D. suzukii infestation compared to untreated control (UTC) treatments, with statistical differences in all three locations. The numerically lower infestation was found in some cases in ZC-CYAN schedule. Population modeling conducted exclusively for blueberry, and the simulations indicated no discernible differences between the two respective schedules (ZC-CYAN vs CYAN-ZC). The present study demonstrates that seasonal infestation of D. suzukii could be suppressed irrespective of application order. Additional research is required to assess the optimal timing and sequence of insecticide applications for controlling seasonal populations of D. suzukii in fruit crops. Such information could be invaluable for growers who are seeking to strategize their insecticide applications.
草莓实蝇（双翅目：果蝇科）是软肉水果（如黑莓和蓝莓）的主要害虫。不同的季节性喷雾方案预计会对草莓实蝇种群产生不同的影响。在美国三个地点（佐治亚州、俄勒冈州和北卡罗来纳州）的蓝莓和黑莓作物上进行了半田间笼式试验，以评估这一假设。在大型笼内进行的田间试验中，使用了不同功效率的杀虫剂（ZC-氯氰菊酯、SPI-乙基多杀菌素、CYAN-氰虫酰胺）。处理方案包括三次为期三周的两次杀虫剂处理。季节性处理方案的应用顺序为：在兔眼蓝莓和高丛蓝莓上应用 ZC-CYAN 和 CYAN-ZC，外加在黑莓上应用 ZC-SPI 处理。此外，还应用了一个种群模型来模拟俄勒冈州草莓实蝇种群模型中杀虫剂方案的相对功效，该模型基于先前发表的功效、生物学和气象参数。总体而言，与未处理对照（UTC）处理相比，所有方案都导致草莓实蝇感染减少，在三个地点均有统计学差异。在某些情况下，ZC-CYAN 方案的感染率较低。仅针对蓝莓进行的种群建模表明，两种方案（ZC-CYAN 与 CYAN-ZC）之间没有明显差异。本研究表明，无论施药顺序如何，草莓实蝇的季节性感染都可以得到抑制。需要进一步研究以评估控制水果作物中季节性草莓实蝇种群的杀虫剂最佳应用时间和顺序。对于寻求制定杀虫剂应用策略的种植者来说，这些信息可能是无价的。
