1. Climate change affects the life cycle of many species. Yet, responses to yearly variation of weather can either help species track optimal conditions or be maladaptive.
2. We analysed phenological data of 46,479 pine processionary moths (Thaumetopoea pityocampa) during 15 years along an altitudinal gradient in southern France. These larvae were sampled in situ and allowed to pupate in a common garden at lower elevation.
3. Individuals originating from higher elevation emerged earlier than those sampled at low elevation, which suggests local adaptation. Yearly variations in temperature also affected phenology. Warm springs caused an earlier adult emergence, while autumn temperatures had an opposite effect. Environmental cues could thus induce contradictory plastic responses.
4. Synchronization mechanisms were identified. Variability in the duration of the pupal phase is a key parameter to synchronize adult emergence in spite of different larval development rates that only marginally influenced emergence dynamics. Semivoltine individuals experiencing prolonged diapause were synchronized with univoltine individuals emerging the same year.
5. These data highlight some contradiction in the effect of spatial versus temporal variations of the temperature on adult emergence. This suggests that phenological responses to the current climate change cannot easily be anticipated by space-for-time substitution designs.

中文翻译：

---

松行蛾物候学的复杂驱动因素：过去的教训

1. 气候变化影响许多物种的生命周期。然而，对每年天气变化的反应可以帮助物种追踪最佳条件或适应不良。
2. 我们分析了15 年来法国南部海拔梯度的 46,479 只松树游行蛾 ( Thaumetopoea pityocampa ) 的物候数据。这些幼虫在原地取样，并允许在较低海拔的公共花园中化蛹。
3. 来自高海拔的个体比低海拔的个体出现得更早，这表明当地适应。温度的年变化也影响物候。温暖的泉水导致成虫提早出现，而秋季气温则产生相反的效果。因此，环境线索可能会引起相互矛盾的塑料反应。
4. 确定了同步机制。蛹期持续时间的变化是同步成虫出现的关键参数，尽管不同的幼虫发育率仅对出现动态产生轻微影响。经历长时间滞育的半化生个体与同年出现的单化个体同步。
5. 这些数据突出了温度的空间与时间变化对成人出现的影响的一些矛盾。这表明时空替代设计无法轻易预测对当前气候变化的物候反应。