Neoxorides montanus Oehlke, 1966

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 : 13-15

Neoxorides montanus Oehlke, 1966

Figs 5G , 9C , F–G

Neoxorides montanus Oehlke, 1966: 889–890 , fig. 3.

Neoxorides montanus – Kasparyan 1981: 94.

Diagnosis

Neoxorides montanus is a species that is quite variable in size, with a fore wing length of 9–14 mm, on average slightly larger than N. collaris . The metasoma in the female is more elongate with the first tergite about 2.5 times as long as wide ( Fig. 9F ). The ovipositor in the female is usually as long as the metasoma and quite narrow and weak. In mounted specimens it is usually curved downwards, sinuate or curled up due to this weakness. The mid coxae in both sexes are largely yellow apically. The whitish spots along the inner orbits above the antennal scrobes are large and rounded in females ( Fig. 9C ) and the white lines on the sides of the pronotum are wide, usually as wide as the width of the fore femur ( Fig. 5G ). Neoxorides montanus is most similar to N. collaris and N. striatus sp. nov., but is distinguished by the characters given in the key to species and Table 2 .

Material examined

Holotype

CZECH REPUBLIC • ♂; ZMHB.

Paratypes

GERMANY • 3 ♀♀; ZMHB • 1 ♂; NHRS.

Other material

SWEDEN • 6 ♀♀, 2 ♂♂; MZLU, NJ, LW .

FINLAND • 4 ♀♀, 11 ♂♂; MZH .

FRANCE • 2 ♀♀, 2 ♂♂; NHMUK .

GERMANY • 3 ♀♀, 3 ♂♂; MR, NHMUK, MZH .

UKRAINE • 1 ♀; OV .

Ecology

Neoxorides montanus is connected to cerambycids feeding on conifers. It has been reared from larch along with the cerambycid Tetropium gabrieli Weise, 1905 (first author pers. obs.). Most records are from spruce Picea abies (L.) H.Karst. dominated forests, which possibly might indicate that the main hosts are Tetropium fuscum (Fabricius, 1787) and/or T. castaneum (Fabricius, 1787) ( Kenis & Hilszczański 2004) .

Distribution and status in Sweden

Most records are from the southern and central parts of the country, but it can probably be expected to occur also up in the north. Go, Hs, Sm.

Remarks

Among the distinguishing characters used to define and describe N. montanus , the relative length of the basal flagellomeres in the female and the shape of the male genitalia seem to be of limited use. According to the original description, the female of N. collaris is said to have the second flagellomere at most 5.2 times as long as wide while it is at least 5.5 times as long as wide in N. montanus . Given the natural variation in the shape of the flagellomeres (which are often oval in cross section) often amplified during preparation and preservation, this small difference is of no practical significance. The male of N. montanus usually has the parameres (and the hind margins of the tergites) more weakly sclerotized than in N. collaris and N. striatus sp. nov., which often makes them heavily deformed during storage or preparation. Newly hatched specimens or specimens of other species stored in ethanol also often display this deformation, making it hard to draw any definitive conclusions from the shape of the genitalia. We, therefore, recommend that the shape of the parameres is only used in combination with other characters. Apart from the shape of the male genitalia and the shape of the flagellomeres, the only diagnostic character used in the original description is the relative length of the metasomal segments. This seems to be a quite consistent character, but one should be aware that overlap frequently occurs with N. striatus sp. nov. and even N. collaris . During this study, it was also noted that the males of N. nitens and also N. striatus sp. nov. seem to be rather variable regarding the length of the metasomal segments ( Fig. 5 E–F). Both the holotype of N. montanus ( Oehlke 1966) and the lectotype of N. collaris ( Jałoszyński & Wanat 2014) are males, and this variation regarding the relative length of the metasoma could present a problem regarding the identity of the type specimens. However, all males of N. collaris studied by the first author have stouter metasoma, and all males of N. montanus have the more slender form, which indicates that these aberrant forms are rare. The additional colour characters of the lectotype of N. collaris and the holotype of N. montanus , respectively, i.e., the shape of the white spots along the inner orbits above the antennal scobes, also supports the validity of each species.

DNA barcode

The barcode of this species is separated from its closest barcode (in N. striatus sp. nov.) by 4.6% p-distance. The sequence is available on GenBank under accession number: MT 072691 (SK19_37).

Figures

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. 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).