Neoxorides opacus ( Kokujev, 1903 ), 2020

Johansson, Niklas & Klopfstein, Seraina, 2020, Revision of the Swedish species of Neoxorides Clément, 1938 (Ichneumonidae: Poemeniinae) with the description of a new species and an illustrated key to species, European Journal of Taxonomy 680, pp. 1-29 : 16-20

Neoxorides opacus ( Kokujev, 1903) stat. rev.

Figs 4A, D , 6B, D, F , 7A, C , 8 A–C

Xorides opacus Kokujev, 1903: 287 .

Xorides kissi Ulbricht, 1911: 151 .

Neoxorides opacus – Clément 1938: 518.

Neoxorides nitens (partim) – Oehlke 1966: 888–889.

Diagnosis

Neoxorides opacus ( Fig. 8 A–B) is distinguished from other species of Neoxorides by the combination of the densely punctate and partly rugulose mesosternum, mesopleuron and metapleuron ( Fig. 4A ), the roughly sculptured propodeum ( Fig. 6B ) and face, the apically wider mandibles ( Fig. 7C ), the dark pronotum and palpi, and the rounded shape of the male parameres ( Fig. 6D ). It is, despite the previously suspected synonymy with N. nitens , most likely to be confused with dark-coloured specimens of N. striatus sp. nov., but has the mandibles stouter and the mesopleuron and mesosternum more densely and distinctly punctate. The structure of the propodeum basally ( Fig. 6B ) and the basal tergites ( Fig. 4D ) are largely rugulose in N. opacus while they are more or less aciculate in N. collaris ( Fig. 6A ), N. montanus and N. striatus sp. nov. Furthermore, the white stripe along the inner orbit of both sexes is usually continuous in N. collaris ( Fig. 7B ), while it is interrupted at the level of the antennal scrobes in all known specimens of N. opacus ( Fig. 7A ).

Material examined

Neotype (here designated)

RUSSIA • ♀; “Région du Baïkal, Environ d’Irkoutsk” [Baikal area, surroundings of Irkutsk]; “174-96”; J. Chaffanjon leg.; MNHN.

Other material

RUSSIA • 1 ♀; MR .

ROMANIA • 1 ♀, lectotype of Neoxorides kissi ( Ulbricht, 1911) ; “Ferenczfalva” [Văliug]; coll. Z. Kiss E.; HNHM-HYM 104461 • 1 ♂, paralectotype of Neoxorides kissi ( Ulbricht, 1911) ; “Ferenczfalva” [Văliug]; coll. Z. Kiss E.; HNHM-HYM 104465 (coll. Z. Kiss E.).

SWEDEN • 15 ♀♀, 4 ♂♂; NHRS, MZLU, NJ, JA .

SOUTHERN EUROPE • 1 ♀; coll. Förster; ZMHB .

Redescription

Fore wing length 8.5–13.5 mm. Antenna in both sexes with 29–32 flagellomeres. First to fourth flagellomere about 5.0 times as long as wide. Central flagellomeres stout, about 1.5–1.7 times as long as wide. Subapical flagellomeres approximately 0.8–1.0 times as long as wide. Temple slightly widened behind eyes in dorsal view, with coarse scale-like structure following outer and upper margin of compound eye. Frons above antennal sockets weakly transversely striate ( Fig. 7A ). Head dorsally, behind compound eyes, with rather distinct punctures that are denser and more distinct than in N. collaris . Inner orbits strongly converging ( Fig. 7A ). Face below antennal sockets rugulose. Mandible chisel-shaped, with more parallel sides and wider edge ( Fig. 7C ) than in N. collaris ( Fig. 7D ) and N. nitens . Malar space short, about 0.1 times as wide as mandibular base ( Fig. 7A, C ). Wing membrane clear ( Fig. 8B ). Pronotum centrally unmodified, not raised as in N. nitens . Mesosternum and mesopleuron densely punctate, partly rugulose ( Fig. 4A ) with punctures denser and more distinct than in N. collaris ( Fig. 4B ) and denser than in N. nitens ( Fig. 4C ). Mesopleural furrow with transverse carinae ( Fig. 6F ). Mesoscutum densely punctate on sides, punctures often merging. Mesoscutum centrally transversely strigose. Notauli deeply impressed, dividing mesoscutum into three lobes. Scutellum with deep punctures on a mostly polished surface. Propodeum basally rugulose ( Fig. 6B ), while it is smoother and slightly aciculate in N. collaris ( Fig. 6A ), N. montanus , N. striatus sp. nov. and N. nitens , and centrally in front of area petiolaris with irregular transverse ridges. First tergite in female 2–2.5 times as long as wide ( Fig. 4D ). Sclerotised section of the first sternite with a raised keel-like projection centrally. First tergite with coarse sculpture consisting of transverse striation centrally and irregular punctures on the sides ( Fig. 4D ), the striae larger than in other species of the genus. Second tergite in female distinctly punctate-rugulose, basally striate, tergites 3–7 weakly transversely aciculate. Second tergite in male distinctly punctate. Tergite 3–7 in male polished with very weak rather scarce punctures that are more distinct basally on tergite 3. Male parameres apically rounded, about as long as wide ( Fig. 6D ), thereby differing from more elongate and apically narrowed parameres of N. collaris ( Fig. 6C ) and N. nitens . Note that the usually more weakly sclerotized parameres in N. collaris , N. montanus , N. striatus sp. nov. and N. nitens are more often deformed due to being dried up. Ovipositor sheath pilose, about as long as the fore wing ( Fig. 8B ).

Colouration

Body black. Inner orbit in female with a white stripe that is interrupted level with antennal sockets ( Fig. 7A ). Face entirely, a line along the inner orbits above the antennal sockets, isolated from the white colouration of the face, and the ventral side of scapus white in male. Tegulae and palpi black or brownish. Tegulae in the neotype of N. opacus ( Figs 8 A–C) and lectotype of N. kissi more whitish. Palpi occasionally paler light brown. Antennae black. Wing veins fuscous and pterostigma testaceous, fuscous along anterior margin. All coxae orange in male and female without any trace of yellow or white markings. Coxae sometimes with infuscate spot basally. Legs orange, hind tibia and hind and mid tarsi black, hind tibia sometimes brownish in basal 0.1. Joint between hind trochantellus and femur slightly infuscate. Fore and mid femur and tibia sometimes yellow anteriorly.

Ecology

All specimens for which the dates of collection are known were collected between late April and late August, indicating a prolonged period of activity or two overlapping generations. The dates of the collected specimens indicate that the main period of activity is May in Sweden. Two series, each consisting of five specimens, were collected by Malaise Traps placed near fresh logs and high stumps of aspen Populus tremula L. An identical trap, next to a pile of logs of Betula L. spp., Alnus glutinosa (L.) Gaertn. and Salix caprea L. between the two Populus L. traps caught no individuals. The two specimens collected with window traps in Grytsbergen and Tasvik in Östergötland have the sclerotization of the cuticula and wing veins weakly developed, indicating that they were newly hatched when they were collected. Both of these localities were involved in a project to investigate the species richness of saproxylic Coleoptera on aspen, and the traps were mounted on dead or dying trunks of aspen (Håkan Andersson, Linköping, pers. com.). Five of the remaining known Swedish specimens were collected in traps adjacent to or attached to dead trunks of aspen. These records could indicate that the host or hosts are to be found among cerambycids feeding on aspen. Xylotrechus rusticus (Linnaeus, 1758) and Saperda perforata (Pallas, 1773) are both common species at the Björneberg locality, where seven females and four males were collected. Both of these species have wide Palaearctic distributions.

Distribution and status in Sweden Widespread in the eastern parts of Southern and Central Sweden in areas with aspen. Gs, Sö, Ög, Öl.

Remarks

The status of N. opacus has historically been subject to different interpretations. Clément (1938) treated it as a valid species based on the original description and proposed N. kissi to be a junior synonym, but Oehlke (1966) put N. opacus and N. kissi in synonomy with N. nitens , referring to a couple of morphologically deviant females, one from Germany and one from Southern Europe. However, he qualified the synonymy with a question mark and stated that he was doubtful whether N. opacus and the apparently conspecific N. kissi are to be regarded as varieties of N. nitens or as valid species. The holotype of N. opacus , a single female collected in Irkutsk in the Siberian Far East ( Kokujev 1903), is lost ( Townes et al. 1960), and there is no known additional material of the species determined by Kokujev (Andrey Khalaim, ZIN, pers. com.). However, in the MNHN, there is a specimen referred to by Clément (1938). This specimen was collected in the vicinity of Irkutsk by the French explorer Jean Chaffanjon (spelled “Chaffaniou” in Clément 1938) and corresponds to the interpretation of N. opacus presented in this study. As this specimen originates from the type locality, it is hereby designated as neotype ( Fig. 8 A–C). One of the two female specimens listed by Oehlke (1966) as “ N. nitens var. opacus ”, the one in the Förster collection in Berlin, has been studied and it is in agreement with the interpretation of N. opacus presented here. The other, collected in Sachsen, Germany, seems to be lost (Jutta Helbig, ZMHB, pers. com.). The female lectotype of N. kissi and one quite badly damaged male paralectotype in the HNHM, collected in Ferenczfalva, Hungary (now Văliug, Romania) also fits the interpretation of N. opacus as defined in this study and the synonymy between N. kissi and N. opacus , previously proposed by Clément (1938), is hereby confirmed.

DNA barcode

The barcode of this species is separated from its closest barcode (in N. collaris ) by 7.0% p-distance. The sequence is available on GenBank under accession number: MT 072692 (SK19_38).

Figures

Fig. 4. A. Neoxorides opacus (Kokujev, 1903) stat. rev., ♀ (NJ), mesopleuron, lateral view. B. N. collaris (Gravenhorst, 1829), ♀ (NJ), mesopleuron, lateral view. C. N. nitens (Gravenhorst, 1829), ♀ (NJ), mesopleuron, lateral view. D. N. opacus, ♀ (NJ), basal portion of metasoma, dorsal view. Photos: Alexander Berg.

Fig. 6. A. Neoxorides collaris (Gravenhorst, 1829), ♀ (NJ), propodeum, dorsal view. B. N. opacus (Kokujev, 1903) stat. rev., ♀ (NJ), propodeum, dorsal view. C. N. collaris, ♂ (NJ), parameres, lateral view. D. N. opacus, ♂ (NJ), parameres, lateral view. E. N. collaris, ♀ (NJ), mesopleural furrow, lateral view. F. N. opacus, ♀ (NJ), mesopleural furrow, lateral view. Photos: Alexander Berg.

Fig. 7. A. Neoxorides opacus (Kokujev, 1903) stat. rev., ♀ (NJ), head, anterior view. B. N. collaris (Gravenhorst, 1829), ♀ (NJ), head, anterodorsal view. C. N. opacus, ♀ (NJ), mandible, lateral view. D. N. collaris, ♀ (NJ), mandible, lateral view. Photos: Alexander Berg.

Fig. 8. Neoxorides opacus (Kokujev, 1903) stat. rev., ♀, neotype (MNHN). A. Head and mesosoma, lateral view. B. Habitus, lateral view. C. Labels. Photos: Claire Villemant.