Data from: Dissecting the contributions of plasticity and local adaptation to the phenology of a butterfly and its host plants

Phenology affects the abiotic and biotic conditions that an organism encounters and consequently its fitness. For populations of high latitude species, spring phenology often occurs earlier in warmer years and regions. Here we apply a novel approach to decompose spatiotemporal covariation between spring temperature and the phenology of two flowering plants, Cardamine pratensis and Alliara petiolata, and a Lepidopteran herbivore, Anthocharis cardamines, across the UK, into the contributions of plasticity and local adaptation. All three species overlap in the time-window over which mean temperatures best predict variation in phenology and we find little evidence that the position of time-windows varies latitudinally, as expected if they were initiated by day-length. The focal species show pronounced temperature-mediated phenological plasticity of similar magnitude. While we find no evidence for local adaptation in the flowering times of the plants, geographic variation in the phenology of the butterfly reveals countergradient local adaptation. Geographic variation in the butterfly's phenology appears to be more sensitive to variation in temperature than the flowering times of the host plants and we find no evidence that coevolution has generated geographic variation in adaptive phenological plasticity.

物候学（Phenology）会影响生物体所遭遇的非生物与生物条件，进而影响其适合度。对于高纬度物种的种群而言，在更温暖的年份与区域，春季物候通常出现得更早。本研究采用一种新颖的方法，将英国境内春季温度与两种开花植物——草地碎米荠（*Cardamine pratensis*）和蒜芥（*Alliaria petiolata*），以及鳞翅目食草昆虫尖翅粉蝶（*Anthocharis cardamines*）——的物候之间的时空协变关系，分解为表型可塑性（plasticity）与本地适应（local adaptation）的贡献。三种研究对象物种的平均温度最能预测物候变异的时间窗口存在重叠，且我们几乎未发现时间窗口的位置随纬度发生变化的证据——这与“时间窗口由日照长度启动”的预期相悖。研究对象物种均表现出程度相近的、温度介导的显著物候可塑性。尽管未发现植物开花时间存在本地适应的证据，但蝴蝶物候的地理变异却显示出逆梯度本地适应。相较于宿主植物的开花时间，蝴蝶物候对温度变异更为敏感，且未发现协同进化（coevolution）催生适应性物候可塑性的地理变异的证据。