Phenological divergence between flowering plants and flower-visiting Lepidoptera under climate change across Europe

Climate change is altering life-cycle timing and may disrupt coordinated interactions between flowering plants and flower-visiting insects. Using Global Biodiversity Information Facility observation records from Europe between 2000 and 2024, we compiled a continental-scale phenological dataset covering flowering periods of 707 angiosperm species and adult activity periods of 620 Lepidoptera species. We extracted the 10th, 50th and 90th percentiles and activity-window width and used linear mixed-effects models to analyse spatio-temporal trends. The results showed that plant phenology advanced significantly, with the 10th and 50th percentiles shifting earlier by −0.597 and −0.507 d yr⁻¹, respectively, whereas the 90th percentile showed no significant change; flowering-window width increased by 0.361 d yr⁻¹. By contrast, Lepidoptera phenology advanced evenly across the season, with the 10th, 50th and 90th percentiles shifting by −0.137, −0.153 and −0.155 d yr⁻¹, respectively, while activity-window width showed no significant change. Because flowering plants advanced faster than Lepidoptera in the early and middle season, plant–insect phenological overlap declined at 0.340 d yr⁻¹, indicating increasing mismatch across Europe. Further analyses identified temperature as the dominant driver of phenological advance in both groups, but flowering plants and Lepidoptera differed in their responses to other climatic factors. These results suggest that climate change is weakening phenological synchrony between flowering plants and flower-visiting Lepidoptera, with potential consequences for pollination and ecosystem functioning.