Circumscription and diagnosis of the Arge ochropus species–group (Hymenoptera: Argidae), with a description of Arge gussakovskiji sp. nov. from the Pamir Mountains in Tajikistan

The species composition and diagnostic characters of the Arge ochropus species–group are reviewed. This species group is circumscribed based on the structure of the genitalia. It contains only four species, including A. gussakovskiji sp. nov. described here from the Pamir Mountains in the Gorno-Badakhshan Province of Tajikistan. A key to the Palaearctic species of the A. ochropus group is provided. The differences between the A. ochropus group and the other species groups of the genus Arge Schrank, 1802 with similar coloration are discussed.