Pre-Bloom Application of Petroleum Spray Oil for the Control of Green Apple Aphid, Aphis pomi DeGeer in Apple Orchards [Data]

The green apple aphid (Aphis pomi DeGeer) is a key early-season pest in apple orchards. Petroleum spray oils (PSOs), are routinely applied at the delayed dormant stage for managing pests like San José scale and European red mite. However, their impact on A. pomi has not been thoroughly evaluated. This study evaluated the ovicidal and larvicidal efficacy of PSOs (2% v/v) applied at the delayed dormant/green tip stage in apple orchards in Jammu and Kashmir, India. Laboratory and field assays demonstrated substantial suppression of egg hatch, with cumulative hatch reduced to 9.90 ± 0.57% (laboratory assay) and 9.62 ± 0.71% (field evaluation) in treated shoots compared to 46.91 ± 0.68% and 53.25 ± 3.25% in controls, respectively. Survival analyses revealed significantly higher mortality risk for treated eggs. Direct toxicity trials on nymphs showed mortality rates of 69.9 ± 1.95% in field conditions and >99% in lab dip assays by 5 days after treatment. Residual toxicity assays indicated cumulative mortality reaching 64.07 ± 2.74 % by 2 days post-exposure, confirming efficacy even after drying. Field trials further revealed that PSO significantly reduced bud infestation by A. pomi (5.22 ± 0.54%) compared to the untreated control (19.04 ± 2.34%), with enhanced suppression observed when combined with imidacloprid (0.29 ± 0.14%). These findings underscore the potential of PSO as both a standalone and synergistic agent in aphid management, particularly when integrated with systemic insecticides. This is the first detailed report on the ovicidal and larvicidal activity of PSOs against A. pomi, supporting its inclusion in sustainable, early-season integrated pest management programs.绿苹果蚜（Aphis pomi DeGeer）是苹果园生长季早期的关键害虫。石油喷雾油（PSOs）通常在延迟休眠期施用，用于防治桑白蚧（San José scale）与欧洲红螨等害虫，但其对绿苹果蚜的影响尚未得到全面评估。本研究针对印度查谟和克什米尔地区的苹果园，评估了在延迟休眠/绿尖期施用2%体积比的PSOs的杀卵与杀若虫效力。实验室与田间试验结果显示，处理组枝条的卵孵化受到显著抑制：实验室试验中累积孵化率降至9.90±0.57%，田间评估中为9.62±0.71%，而对照组分别为46.91±0.68%与53.25±3.25%。生存分析结果表明，处理组卵的死亡风险显著升高。针对若虫的直接毒性试验显示，施药后5天，田间条件下若虫死亡率达69.9±1.95%，实验室浸药试验中死亡率超过99%。残留毒性试验表明，暴露2天后累积死亡率可达64.07±2.74%，证实PSOs在干燥后仍具备防治活性。田间试验进一步显示，与未处理对照组（19.04±2.34%）相比，PSOs可显著降低绿苹果蚜的芽梢侵染率（5.22±0.54%）；当与吡虫啉复配使用时，防治效果进一步提升（0.29±0.14%）。本研究结果证实，PSOs既可单独用于蚜虫防治，也可作为增效剂与内吸性杀虫剂复配，具备良好的应用潜力。这是首份关于PSOs对绿苹果蚜杀卵与杀若虫活性的详细研究报告，为将其纳入可持续的生长季早期害虫综合治理项目提供了科学支撑。