Diagnostics of Polymerus Hahn (Heteroptera, Miridae) Species Group Including Agricultural Pests in the East European Forest-Steppe, Based on Morphological and Molecular Characters

The paper presents an improved key to the co-occurring species of Polymerus Hahn, 1831 (Heteroptera, Miridae) based on morphological characters and our new data on the differences between the COI gene DNA sequences of these species. These characters, together with the data stored in the NCBI GenBank, provide the means for accurate and rapid identification of adults and nymphs of Polymerus unciniger Gapon, 2014, P. unifasciatus (Fabricius, 1794), P. cognatus (Fieber, 1858), P. vulneratus (Panzer, 1806), and P. brevicornis (Reuter, 1879). The subgenera Poeciloscytus Fieber, 1858 and Pachycentrum Gapon, 2014 differ considerably in morphological and molecular genetic characteristics. A PCR-RFLP method has been developed for rapid identification of the pest species P. vulneratus. The morphological characters of P. unifasciatus and the COI gene sequences of the forms earlier registered in GenBank as P. unifasciatus and P. microphthalmus (Wagner, 1951) reveal high intrapopulation variability. Polymerus microphthalmus may be a submacropterous form of P. unifasciatus with shortened hemelytra and smaller eyes, while the macropterous form of the latter species is characterized by larger eyes.