Integrative Approach for the Identification and Delimitation of Orthops Species (Heteroptera, Miridae, and Mirinae) in the Palearctic

Abstract

Orthops is a widely distributed plant bug genus comprising 35 species. Its nominotypical subgenus includes seven species mostly known from the Palearctic, and four of them are widely distributed. Most of them live in sympatry having only little morphological differences. The species limits have never been tested using the molecular data. The aim of this work is to test whether currently defined species represent monophyletic lineages and to find their interrelationships using an integrative approach. Morphological studies on external characters and male and female genitalia were performed. The molecular studies were based on the mitochondrial (cytochrome c oxidase subunit I [COI] and 12S ribosomal RNA [rRNA]) and nuclear (internal transcribed spacer I [ITS1] and calcium ATPase [Ca-ATPase]) markers and included comparison of the intra- and interspecific distances, species delimitation (ABGD, BPP, bGMYC, PTP, and bPTP), and phylogenetic analyses. All markers showed interspecific differences, and COI was the most variable. It was found that all species differed from each other morphologically, and the most reliable character complexes were parameres and female genitalia. In most analyses, Orthops kalmii and O. campestris were monophyletic. Orthops basalis formed a clade in most phylogenetic trees. Most of the species delimitation analyses confirmed the status of those three species. Orthops scutellatus was split into two clades, Palearctic and North American, which was also confirmed by the species delimitation analyses. Those two groups differed in parameres. Orthops campestris and O. scutellatus form a clade in all analyses, and O. basalis forms a clade with O. kalmii in most analyses.