Ophion subarcticus Hellén, 1926

Johansson, Niklas & Cederberg, Björn, 2019, Review of the Swedish species of Ophion (Hymenoptera: Ichneumonidae: Ophioninae), with the description of 18 new species and an illustrated key to Swedish species, European Journal of Taxonomy 550, pp. 1-136 : 99-101

Ophion subarcticus Hellén, 1926

Figs 18B, D , 42

Ophion subarcticus Hellén, 1926: 12–13 .

Material examined

Lectotype, ♀, and paralectotype, ♀ ( MZH); 2 ♀♀ ( Sweden).

Diagnosis

Fore wing length 14–15 mm. Antenna with 48–52 flagellomeres. First flagellomere about 3.5–4.0 times as long as wide. Central flagellomeres about 1.5–1.6 times as long as wide. Subapical flagellomeres approximately 1.5 times as long as wide. Temple buccate. Head in lateral view with temple 0.8 times as long as compound eye. Head in anterior view with face wide in relation to the compound eyes ( Fig. 18D ). Gap between compound eye and lateral ocellus very wide, about 0.6–0.7 times the diameter of ocellus ( Fig. 18B ). Malar space about 0.5–0.6 times as long as mandibular base. Gape between mandibles obtuse with internal angles present. Wing membrane yellowish. Ramellus distinct, 0.3 times the width of the discosubmarginal cell. Radius sinuous. Structure of mesopleuron strongly shagreened and wrinkled with distinct punctures. Interstices between punctures at most equal to their diameter, generally much less. Epicnemial carina, in antero-ventral view, with pleurosternal angles obviously anterior to sternal angles. Pleurosternal angles rounded, obtuse to right angled. Scutellum with lateral carinae present in basal 0.7. Anterior transverse carina of propodeum present and quite strong. Posterior transverse carina only present laterally, widely interrupted centrally. Structure of propodeum less polished than in O. kevoensis . Petiolar carina and longitudinal carina delimiting area superomedia weak. Legs normal with hind femur about 6.5 times as long as wide. Hind trochantellus shorter than wide in dorsal view. Inner spur of hind tibia about 0.3–0.4 times as long as metatarsus. Sclerotised part of first sternite ending level to spiracle. Male unknown.

Colour

Mesosoma infuscate, probably distinctly dark brown in fresh specimens ( Fig. 42 ). Mandibular teeth black. Head with antennae and inner and outer orbits weakly yellowish. Metasoma, antennae and legs testaceous. Ovipositor sheath testaceous, of same colour as posterior metasomal segments.

Ecology

Both of the Swedish specimens were collected in areas probably dominated by mature subalpine forests consisting of Scots pine Pinus sylvestris and spruce Picea abies (L.) H.Karst. Unfortunately, no information on flight period or habitat is recorded on the labels.

Distribution in Sweden

Judging from the known specimens, this is an exceedingly rare species. The only known specimens from Sweden are two females, one of which is badly damaged by dermestids, in NHRS collected at the beginning of the 20 th century at Töfsingdalen and Tandådalen in the Province of Dalarna.

Remarks

Ophion subarcticus is similar to Ophion kevoensis but, apart from the distinct colour pattern, is distinguished by the smaller size, the longer malar space, the more shagreened mesopleuron and the more buccate temples with a wider gap between the compound eye and ocellus in dorsal view. It also strongly resemble and is sometimes confused with O. nigricans , a species it is probably closely related to, but O. subarcticus has distinct lateral carinae on the scutellum, a feature absent in O. nigricans . Both the holotype and paratypes in MZH had been determined by Brock as Ophion brevicornis in 1997, but share none of the features defining that species, e.g., the strongly convex uncarinated scutellum, short central flagellomeres or the complete posterior transverse carina of the propodeum.

Figures

Fig. 18. A–B. Head, dorsal view of female. A. Ophion brevicornis Morley, 1915. B. O. subarcticus Hellén, 1926. C–D. Head anterior view of female. C. O. brevicornis. D. O. subarcticus. E–F. Propodeum posterodorsal view of female. E. O. matti Johansson sp. nov., paratype, ♀ (NHRS-HEVA000008679). F. O. ellenae Johansson sp. nov., paratype, ♀ (NHRS-HEVA000008655). G–H. Head in dorsal view of Ophion pteridis Kriechbaumer, 1879. G. Female. H. Male.

Fig. 42. Ophion subarcticus Hellén, 1926, ♀. Scale bar = 1 mm.