Morphological and molecular variability within widespread Palearctic species Liocoris tripustulatus Fieber (Hemiptera: Heteroptera: Miridae: Mirinae)

Abstract

The works addressing the intraspecific genetic and morphological diversity of the widespread Palearctic plant bug species on their entire distribution ranges are rare. In this study the morphological and molecular variability of Liocoris tripustulatus Fieber, 1858 was assessed. The molecular diversity was investigated based on two mitochondrial markers (cytochrome c oxidase subunit I or COI and 16S rRNA) and a nuclear marker (internal transcribed spacer 1 or ITS1). The genetic, haplotype and population diversity were assessed. The phylogenetic analyses and automatic species delimitation were performed to test for the possible cryptic species. The dating analysis was performed to estimate the clade divergence time. The results showed that the coloration of this species is variable, however, structures are stable, showing some variability in the right paramere shape and sclerotization of the female genitalia. The genetic diversity within the species is shallow. The phylogenetic analyses based on the mitochondrial markers show that the specimens from Georgia and Iran form a well-supported clade. In the phylogenies based on ITS1 specimens from Dagestan Republic (Northern Caucasus) are also included into this clade. The Caucasian-Iranian clade might represent a separate population or species at the early stages of its separation, which originated during the Middle Pleistocene.