Neogene climatic fluctuations and poor connectivity with the centres of diversity shaped the Western Palaearctic net-winged beetle fauna

Only 22 net-winged beetle species (Elateroidea: Lycidae) are known from the Western Palaearctic region (WPR), i.e. less than 0.5% of the global lycid diversity and much fewer than from similar latitudes of East Asia or Northern America. We used comprehensive distribution data and a molecular phylogeny of similar to 400 world lycids, including 14 European species, to provide a new perspective for understanding the structure and evolution of this group in the WPR. All Mediterranean species represent deeply rooted lineages with relatives in eastern Asia. These species occur in relictual ranges close to the family's Pleistocene refugial edge. The phylogeny points to the loss of biological connection with East Asia since the Mid-Miocene. A third of WPR species is widespread in Central and Northern Europe, reaching eastern Asia, some of them possibly younger elements of the European fauna. Unlike the relatively high diversity in the Eocene amber, the extant net-winged beetles represent a small fraction of elateroid diversity in the WPR and are generally rare. Therefore, we assume that most WPR species are relics trapped in Mediterranean refugia since the onset of the Plio-Pleistocene cooling and are critically endangered by the ongoing loss of suitable habitats.