Integrative taxonomy reveals cryptic speciation in the anthidiine wool carder bee Anthidium loti Perris, 1852 (Hymenoptera: Megachilidae) in the Western Palaearctic

The Mediterranean, the Irano-Anatolian and the Caucasus regions are known as major biodiversity hotspots with high speciation dynamics in many groups of plants and animals. In order to better understand underlying processes, the situation of the wool carder bee Anthidium loti, a pollinator whose distribution extends from the Mediterranean into Central Asia and Pakistan, was examined. Despite a high level of geographic variation in the colour pattern, it was found that colouration does not correspond to distinct population groups. However, genetic examination of the COI mitochondrial marker and the LW-rhodopsin nuclear one from populations of the entire distribution range revealed that there are two distinct groups: eastern and western. Phylogenetic analysis showed that these two groups belong to monophyletic clades and multiple species delimitation analyses confirmed the presence of two well distinct species within A. loti s.l. Further evidence for the presence of distinct taxa was obtained by a multivariate Discriminant Function Analysis of nine morphometric parameters, which allowed us to correctly assign 93.8% of all specimens to the respective species. Based on these results and the examination of the historical type material, the western population group was assigned to Anthidium loti Perris 1852, and the eastern population group to Anthidium regulare Eversmann 1852, which has previously been regarded as a synonym. The taxonomic status is hereby re-established (stat. resurr.), and a lectotype is designated. This study adds novel evidence to the growing body of knowledge demonstrating a high cryptic diversity in the Mediterranean region.