Global change drives phenological and spatial shifts in Central European longhorn beetles (Coleoptera, Cerambycidae) during the past 150 years.

Temperature increases and land-use changes induce altered annual activity periods of arthropods. However, sufficiently resolved long-term data sets (> 100 years) are mostly missing. We use a data set of longhorn beetle records (71 species) collected in Luxembourg 1864-2014. Increase of annual temperatures was significantly correlated with an earlier annual appearance. Forty-four species present before and after 1980 appeared on average 8.2 days earlier in the year in the more recent period. Since 1950, the estimated shift was 0.26 days per year. Increase of temperature in spring (March-June) preponed the first appearance of beetles by on average 9.6 days per 1 °C. We found significant changes in the composition of beetle communities, with a net gain in species richness during the last 40 years. Eleven species recorded only after 1997 were characterized by comparatively early annual appearance. Smaller beetles tended to appear earlier in the year in comparison to large-bodied species. Shifts in phenology did not correlate with species Red List status. As also demonstrated by our data, climate change in general affects insect phenologies and changes species composition. However, land-use change has taken place in parallel with climate change. Both aspects of global change are influencing the changes in longhorn beetle occurrences in Luxemburg in their combination. This might be most clearly reflected in the strong decrease of species with continental climate niches dwelling in old-growth deciduous forests that apparently are threatened by the loss of these habitats and increasing spring temperatures.