The role of climate and biotic factors in shaping current distributions and potential future shifts of European Neocrepidodera (Coleoptera, Chrysomelidae)

The Western Paleartic species of Neocrepidodera Heikertinger (Coleoptera: Chrysomelidae: Galerucinae: Alticini) mostly occur in medium and high elevation ecosystems particularly sensitive to climate change. Here, using ensemble projections from state-of-the-art habitat suitability modelling techniques, we investigated how climate change and associated changes in host availability may affect the persistence of three pairs of closely related Neocrepidodera taxa. Modelled niches and suitability patterns reflected the current distributions of the targeted taxa. Neocrepidodera ligurica occupies a small portion of the broader environmental niche of N. melanostoma, and its narrow geographical range makes this species particularly vulnerable to potential loss of suitable habitats in Western Alps. Neocrepidodera cyanescens cyanescens and N. cyanescens concolor were found to occupy separate niches, but the non-significance of the niche similarity test suggested their divergence being probably due to allopatric processes. Neocrepidodera corpulenta and N. rhaetica showed partially overlapping niches, coherently with their co-occurrence in Western Alps. Most of the targeted taxa were predicted to potentially lose large portions of currently suitable areas in the forthcoming decades. Notwithstanding the candidate host plants did not emerge as most important predictors, except Aconitum lycoctonum for N. cyanescens concolor, a clear reduction of potential insect-plant co-occurrence areas resulted for most future scenarios. Climate was confirmed to noticeably affect the distribution of the targeted taxa, among which N. ligurica, N. cyanescens concolor, N. corpulenta and N. rhaetica may need specific prioritisation measures in the future decades, claiming for further attention on mountainous entomofauna in a warming world.