Neoxorides Clément, 1938

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 : 6-8

Genus Neoxorides Clément, 1938

Neoxorides Clément, 1938: 517–519 . Type species: Neoxorides nitens ( Gravenhorst, 1829) .

Molecular Analyses

The barcoding analysis showed small intraspecific and rather large interspecific distances ( Table 1 ), thus confirming all species hypotheses of the taxa treated in this work (with the exception of N. varipes , for which we could not obtain a barcode). The largest intraspecific distance was found in N. collaris (0.8% p-distance), while the minimum interspecific distance was 4.6% (between N. striatus sp. nov. and N. montanus ), leaving a barcoding gap of 3.6% (but this might decrease when more populations of each species are sampled).

The Bayesian phylogenetic analysis ( Fig. 3 ) recovered all the species as monophyletic, although N. collaris was not strongly supported (likely because of one specimen only having half of the barcoding sequence). Neoxorides collaris shows a rather isolated position with respect to the morphologically similar N. striatus sp. nov. and N. montanus , which are recovered as sister groups.

Key to the Western Palaearctic species of Neoxorides

The key to species is quite straightforward, but when separating N. collaris , N. montanus and N. striatus sp. nov., one should be aware that some of the characters partly overlap (see also Table 2 ). The determination should, therefore, be supported by a combination of characters. Generally, the yellow marking on the head and coxae are less distinct in small specimens; nevertheless, the colouration can be useful in species diagnostics. Previously used characters as the shape of the male genitalia and the shape of the flagellomeres ( Oehlke 1966) have been found to be too variable to be of any significant use and are excluded from the key. The measurements of the metasomal segments represent typical specimens, and the overlap makes it necessary to use this character in combination with the other characters given in the key. While the white spots along the inner orbits above the antennal scobes are surprisingly consistent in shape, the white line below the scrobes is very variable within species and can be distinct, diffuse or missing.

The subfamily Poemeniinae can be keyed out using Broad et al. (2018). The genus Neoxorides is then separated from other genera of the subfamily by the scale-like structure of the temples in combination with the entirely black scutellum and the indistinct punctures on the tergites.

1. Scutellum and postscutellum with yellow apices; second and third tergite with distinct punctures .. ........................................................................................ Podoschistus scutellaris (Desvignes, 1856)

– Scutellum and postscutellum black; second and third tergite with indistinct punctures .................. 2

2. Anterior part of pronotum centrally raised as a collar ( Fig. 5C ); mesopleuron and mesosternum polished with scattered punctures ( Fig. 4C ); male with face black centrally. Primarily connected to hosts on oak ......................................................................... Neoxorides nitens ( Gravenhorst, 1829)

– Anterior part of pronotum unmodified; mesopleuron and mesosternum with distinct microsculpture ( Fig. 4 A–B); male with face white ................................................................................................... 3

3. Propodeum dorsally with rugose sculpture ( Fig. 6B ); mandibular teeth wide with almost parallel sides ( Fig. 7C ); pronotum laterally without white line. Possibly connected to hosts on aspen ........................................................................... Neoxorides opacus ( Kokujev, 1903) stat. rev.

– Propodeum dorsally shagreened or with faint striate microsculpture ( Fig. 6A ); mandibular teeth (when unworn) apically narrowed ( Fig. 7D ); pronotum usually with white line laterally (sometimes absent in very small specimens). Primarily connected to hosts on conifers ..................................... 4

4. Hind coxae brown or black; sides of pronotum with weak, reticulate microsculpture ( Fig. 5B ); white spots along inner orbits above antennal sockets very short ( Fig. 5A ) ................................................ ................................................................................................ Neoxorides varipes ( Holmgren, 1860)

– Hind coxae orange; sides of pronotum in lower part polished, without microsculpture ( Fig. 5D, G ); white spots along inner orbits above antennal sockets longer ( Fig. 7B ) .......................................... 5

5. Frons weakly transversely striate over most of its surface ( Fig. 1B ); sides of pronotum in female and male centrally with distinct striae that extend slightly backwards to upper part (as in Fig. 5G ); metapleural furrow with distinct transverse carinae ( Fig. 1C ); pale marks along inner orbits above antennal scrobes in female short, about 2.0–2.5 times as long as wide ( Fig. 9B ); first tergite in female about 2.0–2.3 times as long as wide ( Fig. 9E ); mid coxae in female orange; white stripe on pronotum in male and female slender, at most one third as wide as width of fore femur (as in Figs 1A , 5D ); face in male narrow ( Fig. 9H ) ...................................................... Neoxorides striatus Johansson sp. nov.

– Frons evenly shagreened without obvious striae ( Fig. 7B ); metaplural furrow with transverse carinae less distinct ( Figs 4B , 6E ); if sides of pronotum have striae centrally that extend backwards to the upper part ( Fig. 5G ), then mid coxae have extensive yellowish markings and white line of pronotum is as wide as the width of the fore femur ( Fig. 5G ); face in male usually wider ( Fig. 9G ) .............. 6

6. Sides of pronotum in female and often in male centrally with transverse striae that extend backwards to upper part ( Fig. 5G ); white stripe on pronotum in male and female wider, about as wide as the width of fore femur ( Fig. 5G ); mid coxae in female with extensive yellow or whitish marks on outer side (absent in small females); pale marks along inner orbits above antennal scrobes in female usually stouter, about 2.0 times as long as wide, slightly widened in upper part, rounded ( Fig. 9C ); first tergite in female usually about 2.4–2.5 times as long as wide ( Fig. 9F ), sometimes shorter, in male usually about 3.5 times as long as wide; ovipositor about as long as metasoma, slender and weak, usually curved downwards, sinuate or partly curled up in dried up specimens, rarely evenly upcurved ................................................................................ Neoxorides montanus ( Oehlke, 1966)

– Sides of pronotum centrally usually without microsculpture ( Fig. 5D ), if weak striae are present, they do not extend upwards / backwards; white stripe on pronotum in male and female usually slender (wider in large males), at most 0.5 times as wide as width of the fore femur ( Fig. 5D ); mid coxae orange in female, rarely with small whitish mark apically in large specimens; pale marks along inner orbit above antennal scrobes in female narrower, about 3.0 times as long as wide, parallel or converging in upper part ( Fig. 9A ); first tergite in female usually about 1.7–1.9 times as long as wide ( Fig. 9D ), in male usually about 2.0–2.5 times as long as wide; ovipositor about as long as metasoma minus the first tergite, stouter, curved upwards ................. Neoxorides collaris ( Gravenhorst, 1829)

Figures

Fig. 3. Bayesian majority-rule consensus tree based on CO1 sequences, showing posterior probabilities of the recovered nodes within Neoxorides Clément, 1938.

Fig. 5. A. Neoxorides varipes (Holmgren, 1860), ♀, MZH, head, anterior view. B. N. varipes, ♀ (MZH), pronotum, lateral view. C. N. nitens (Gravenhorst, 1829), ♀ (NJ), central anterior part of pronotum, lateral view. D. N. collaris (Gravenhorst, 1829), ♀ (NJ), pronotum, lateral view. E. N. nitens, ♂ (NJ), form with long metasoma, lateral view. F. N. nitens, ♂ (NJ), form with short metasoma, lateral view. G. N. montanus (Oehlke, 1966), ♀ (NJ), pronotum, lateral view. Photos: Alexander Berg.

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. 1. Neoxorides striatus Johansson sp. nov., holotype ♂ (BC ZSM HYM07485). A. Habitus, lateral view. B. Head, anterior view. C. Mesopleuron, lateral view. Photos: Stefan Schmidt.

Fig. 9. A–C. ♀, generalized shape of head and colouration of face, anterior view. A. Neoxorides collaris (Gravenhorst, 1829). B. N. striatus Johansson sp. nov. (lectotype NHRS-HEVA000011623). C. N. montanus (Oehlke, 1966). D–F. ♀, generalized shape of first tergite, dorsal view. D. N. collaris. E. N. striatus Johansson sp. nov. (lectotype NHRS-HEVA000011623). F. N. montanus. G–H. ♂, generalized shape of head and colouration of face in anterior view. G. N. montanus. H. N. striatus Johansson sp. nov. (paratype NHRS-HEVA000011622).

Tables

Table 1. Uncorrected pairwise distances of species of Neoxorides Clément, 1938.

Species	Max. intraspecific	Min. interspecific	Closest species
N. striatus sp. nov.	0.00%	4.63%	N. montanus
N. caryae	–	8.28%	N. collaris
N. collaris	0.8%	7.01%	N. opacus
N. montanus	–	4.63%	N. striatus
N. nitens	0.46%	7.34%	N. collaris
N. opacus	–	7.01%	N. collaris