An integrative approach to assess the taxonomy and Phylogeography of the genus Liophloeodes Weise 1894 (Coleoptera: Curculionidae)

Liophloeus (Coleoptera:Curculionidae) is a genus of weevils consisting of two subgenera: Liophloeus sensu stricto (including sexual and parthenogenetic taxa with wide range of ecological preferences) and Liophloeodes (including only sexual taxa, connected with wet and cold biotopes, occurs mostly in mountains). Traditional taxonomy of this group is rather poor. Liophloeodes species share similar ecological preferences and almost identical morphology, apart from the shape of aedeagus (part of male genitalia), which is the traditional diagnostic trait for species delimitation. Also their geographical ranges are partially overlapping, however every species has its own distribution pattern connected with mountain massifs- different parts of Carpathians, Alps, Dinaric Alps or other mountains. Therefore, they could be young species or populations under speciation, and their evolution may have been shaped by processes connected to the last glaciation and interglaciation events. It is possible that such species are currently in the “warm-stage” refugia, and the Carpathians (which are the center of Liophloeodes’ range) are one of them. The aim of this study was to delimit species within the genus using an integrative approach based on molecular evidence [by sequencing two nuclear (28S-D2 and ITS2) and one mitochondrial (COI) markers] and morphometric evidence (by measuring several morphological traits). Topology of trees based on nuclear markers was fully congruent with the classification of studied specimens based on their genitalia. However, phylogeny of COI marker was only partially concordant with those results and suggested hybridization between some species. This hypothesis seems to be supported also by heterozygosity detected at nuclear loci. Moreover, results of morphometric study only indicated clear differentiation between Liophloeus sensu stricto and Liophloeodes, which may suggest that Liophloeodes species splitted recently.