With global warming, the mean temperature during the insect development season has been increasing in Switzerland over the last decades, and this trend is predicted to continue. As a result, the annual number of generations could increase for polyvoltine insect species. Some pest species, such as the box tree moth (Cydalima perspectalis), the grapevine moth (Lobesia botrana), the codling moth (Cydia pomonella), and the Comstock mealybug (Pseudococcus comstocki), are therefore likely to produce more generations in the future, leading to more damage to forests, vineyards and crops. These species all have a base development temperature (tb) of around 10 °C. In this study, we examined the extent to which changes in daily mean temperature (Tmean) averaged over the development season (April through September) could potentially increase the voltinism of these species in various regions of Switzerland. We analysed long-term daily Tmean data from the period 1980–2021 at 67 meteorological stations covering an elevation range from 203 to 2283 m a.s.l. We then used two climate scenarios (RCP2.6 and RCP8.5) to analyse daily Tmean during the period 2022–2099. We computed growing degree days (GDDs) above tb = 10 °C and looked at the trends across elevation. Our results show that daily Tmean averaged across the development season increased more than the daily Tmean averaged over the entire year over the last 40 years. There was an average increase of 60 GDDs per decade during this period, with larger increases occurring at lower elevations. Our results indicate that by the end of the 21st century there could be more GDDs on the Swiss Plateau than currently occur at lower elevations on the southern side of the Alps and that the number of GDDs currently occurring on the Swiss Plateau could be found at middle elevations (800–1400 m a.s.l.). Future temperature conditions can thus be expected to favour additional generations of pests annually at lower elevations and to allow them to complete a full single cycle per year at higher elevations.

随着全球变暖，过去几十年瑞士昆虫发育季节的平均温度一直在上升，预计这一趋势将持续下去。因此，多化昆虫物种的年世代数可能会增加。一些害虫种类，例如黄杨树蛾 ( Cydalima perspectalis )、葡萄蛾 ( Lobesia botrana )、苹果蠹蛾 ( Cydia pomonella ) 和康斯托克粉虱 ( Pseudococcus comstocki))，因此很可能在未来产生更多的后代，从而对森林、葡萄园和农作物造成更大的破坏。这些物种的基本发育温度 (tb) 都在 10 °C 左右。在这项研究中，我们研究了发育季节（4 月至 9 月）平均日平均温度 (Tmean) 的变化在多大程度上可能会增加这些物种在瑞士不同地区的伏尔腾现象。我们分析了 1980-2021 年期间 67 个气象站的长期每日 Tmean 数据，这些气象站的海拔范围从 203 到 2283 m asl 然后我们使用两种气候情景（RCP2.6 和 RCP8.5）来分析该期间的每日 Tmean 2022–2099。我们计算了高于 tb = 10 °C 的生长度日 (GDD)，并查看了整个海拔的趋势。我们的结果表明，在过去 40 年中，整个开发季节的每日平均 Tmean 增加超过全年的每日平均 Tmean。在此期间，平均每十年增加 60 个 GDD，在较低海拔地区增加幅度更大。我们的结果表明，到 21 世纪末，瑞士高原上的 GDDs 可能比目前阿尔卑斯山南侧低海拔地区发生的 GDDs 数量更多，目前发生在瑞士高原的 GDDs 数量可能在中部海拔高度（800–1400 m asl）。因此，可以预期未来的温度条件每年有利于较低海拔的害虫世代，并允许它们在较高海拔每年完成一个完整的单一周期。