Diplazon cascadensis Dasch 1964a

Klopfstein, Seraina, 2014, Revision of the Western Palaearctic Diplazontinae (Hymenoptera, Ichneumonidae), Zootaxa 3801 (1), pp. 1-143 : 38

Diplazon cascadensis Dasch 1964a

Diplazon fechteri Diller 1969 (syn. nov.)

Diagnosis. Fore wing length 4.5–5.3 mm. Antenna with 16–18 flagellomeres. Face with punctures disappearing against the coriaceous background. Mesopleuron smooth and polished, weakly punctate on lower half, at most with some weak puncture along the anterior margin on upper half, sometimes with a small, coriaceous area centrally. Propodeum with a full set of carinae enclosing basal, lateral and petiolar areas. Tergite 1 0.9–1.3 times as long as wide in females, 1.4 in males, tergite 2 0.7–0.85 in females and 0.9 in males; tergites 2 and 3 finely rugose or coriaceous and matt, punctures indistinct, smooth and shining behind transverse impressions. Transverse impressions deep on tergites 1 and 2, weak or absent on tergite 3. Female metasoma strongly compressed posterior to fourth segment, knife-like towards apex.

Colouration of females. Antenna dark brown. Head and mesosoma black, face with yellow along inner orbits, without yellow central face patch, yellow on clypeus and mouthparts, hind corner of pronotum, tegula, small to medium-sized shoulder mark, upper or whole mesepimeron, brown or yellow on subtegular ridge; scutellum yellow. Legs orange, coxae black, fore and mid coxa with a yellow apex; femora orange; hind tibia brown-whitebrown banded, hind tarsus dark brown. Metasoma black, second and often third tergite often with orange hind margins.

Colouration of males. As in females but with yellow ventrally on scape and pedicel, entire face, propleuron, mesopleuron and mesosternum in front of epicnemical carina, and a spot low on posterior half of mesopleuron. Fore and mid coxae and trochanters yellow, hind coxa with yellow apex, fore and mid legs often yellow. Metasoma with orange hind margins on tergites 1 to 7.

Material examined. Paratype of Diplazon cascadensis Dasch : USA, Alberta, Banff, 7,000–8,000 ft in the Cascade Mts, leg. O.Bryant, 20.VII.1925, 1♀, at USNM. Holotype of Diplazon fechteri Diller : Switzerland, Valais, Morteratsch, 1900m, leg. Schacht, VII.1972. 1♀, at ZSM.

Additional material examined. USA, Wyoming, Teton N.For., Snake River, leg. B. and C. Dasch, 9.VII.1978. 1♂, 1♀, at AEI.

Notes. This species is known from only five specimens from the US, the female holotype of D. fechteri from Switzerland, and one female collected in Russia ( Manukyan 1995). As the latter could not be seen, the description is based on the Swiss specimen and the North American material.