Diplazon hyperboreus ( Marshall 1877, Bassus

Klopfstein, Seraina, 2014, Revision of the Western Palaearctic Diplazontinae (Hymenoptera, Ichneumonidae), Zootaxa 3801 (1), pp. 1-143 : 40

Diplazon hyperboreus ( Marshall 1877, Bassus )

Diplazon algidus Dasch 1964a

Diagnosis. Fore wing length 3.9–5 mm. Antenna of both sexes with 15–17 flagellomeres. Face with punctures disappearing against the coriaceous background. Mesopleuron coriaceous and matt on part of its surface, with some very weak punctures. Propodeum with a full set of carinae enclosing basal, lateral and petiolar areas. Tergite 1 1.0–1.25 times longer than wide in females, 1.1–1.5 in males, tergite 2 0.65–0.9 times as long as wide in both sexes; tergites 2 and 3 strongly coriaceous and matt, punctures indistinct, sculpture extending across transverse impressions. Transverse impressions deep on tergites 1 to 2 and often 3. Metasoma evenly tapered posterior to third segment.

Colouration of females. Antenna black. Head and mesosoma black, face with yellow along inner orbits, without yellow central face patch, yellow on clypeus and often mouthparts, hind corner of pronotum, remainder of yellow colouration usually reduced; scutellum at most with a yellow tip. Legs orange, coxae black or sometimes red; femora orange, often marked with black below; hind tibia black-white-black banded, sometimes apical band with an orange or orange-brown area, hind tarsus dark. Metasoma black.

Colouration of males. As in females but with yellow ventrally on scape and pedicel and sometimes antenna, central yellow face patch or entire face. Fore and mid coxae yellow apically.

Material examined. Lectotype and paralectotype of Bassus hyperboreus Marshall : Norway, 19.VII.1873. 2♂, at BMNH. Paratypes of Diplazon algidus Dasch : USA, Alaska, Mt. McKinley, 3500', leg. David Townes, 5. and 7.VIII.1954. 2♀, at AEI. USA, Alberta, Banff, leg. E.H.Strickland, 8.VIII.1949. 1♂, at AEI.

Canada (1), Denmark ( Greenland: 1), Norway (3), Sweden (13), USA (4).

Distribution. Holarctic.