Pristiphora staudingeri (Ruthe, 1859)

Nematus Staudingeri [sic!] Ruthe, 1859: 306-307. Lectotype ♀ (designated by Vikberg 1978) in NMW, examined. Type locality: Iceland.

Pristiphora circularis Kincaid, 1900: 350. Holotype ♀ (USNMENT00778165) in USNM, not examined. Type locality: Popof Island, Alaska, USA.

Pristiphora hyperborea Malaise, 1921: 11. Lectotype ♀ (NHRS-HEVA000003650; designated by Vikberg 1978) in NHRS, examined. Type locality: Torne Träsk, Torne Lappmark, Sweden.

Pristiphora asperlatus Benson, 1935: 35-38. Holotype ♀ in BMNH, not examined. Type locality: Mount Braeriach, Inverness, Scotland, United Kingdom.

Similar species.

Based on the external morphology, the most similar species are P. astragali, P. confusa, P. luteipes, P. opaca, P. pusilla, P. sootryeni, and P. subopaca . The combination of usually strongly coriaceous sculpture on the mesepisternum (Fig. 20), the habitat (arctic or subarctic), and the structure of the lancet (absence of small spiny pectines or dentes semicirculares and well developed ctenidia; Figs 73-76) or penis valves (Figs 97-100, 102) should usually enable distinction of the species from other similar species. Vikberg (1978) treated P. hyperborea Malaise tentatively as a separate species, but no characters distinguish it unambiguously from P. staudingeri . The small differences in lancets (Figs 73-76), penis valves (Figs 97-100, 102) and the sculpture of the mesepisternum most likely represent within species variation and therefore we treat P. hyperborea as a synonym of P. staudingeri as suggested by Lindqvist (1953). In addition, penis valves and lancets cannot be distinguished from P. luteipes and P . beaumonti (see under P. luteipes) (Figs 60-61, 101, 103), which can have a completely smooth mesepisternum (Fig. 19) and can be extremely pale (Fig. 13). Because of the black metafemur, females of P. staudingeri can easily be distinguished from P. luteipes (completely yellow metafemur; Fig. 23), but two studied Swedish specimens ( Jämtland County at an altitude 900 m) had an apically slightly yellow (W10115) or even apically half yellow metafemur (W10105), weakening the distinction between these taxa.

Genetic data.

Based on COI barcode sequences, belongs to the same BIN cluster (BOLD:AAG3568) as P. aphantoneura, P. bifida, P. confusa, P. opaca, P. pusilla, and P. subopaca (Fig. 1). The nearest neighbour (BOLD:AAQ2302, P. armata and P. leucopus) is 2.76% different. It is not clear if nuclear TPI sequences allow better identification of P. staudingeri compared to COI barcode sequences, mainly because the identity of the male specimen DEI-GISHym80049 (Fig. 2) is uncertain. According to TPI sequence, this male from Sweden is closer to P. luteipes (males of which are not known from northern Europe for certain) than to P. staudingeri (Fig. 2), but morphological characters and collecting locality ( Härjedalen at an altitude of 840 m) does not allow for certain identification. In addition, COI barcode of DEI-GISHym80049 is identical to one of the P. staudingeri specimens (Fig. 1).

Host plants.

Salix herbacea L. and S. phylicifolia L. (Vikberg 1978).

Distribution and material examined.

Western Palaearctic, Nearctic. Specimens studied are from Finland, France, Great Britain, Iceland, Norway, Sweden, and Switzerland. The species should be removed from the fauna of Denmark. Publications (e.g. Taeger et al. 2006) mentioning this species from Denmark are based on misinterpretation of Nielsen and Henriksen (1915), who actually recorded P. albitibia under the name P. staudingeri, as evidenced by the mentioned hostplant, Vicia cracca .