226 Euura septentrionalis (Saarinen, 1950)

Figs 249, 464

Amauronematus septentrionalis Saarinen, 1950b: 54–58 .

Nematus taiganus Zhelochovtsev, 1988: 98 . Synonymy by Schmidt (1997).

Diagnosis

Morphologically very similar to E. striata and E. tenuis . Lamnium 1.9–2.2 times as long as radix seems to distinguish the females from those of E. striata (usually 1.6–1.7 times as long). Euura tenuis seems to be usually somewhat smaller (5.5–8.0(8.8) mm; this study; Schmidt 1997) and have a darker pterostigma (dark brown or grey) than E. septentrionalis ((7.1)8.0– 9.7 mm, pterostigma centrally pale brown; this study; Schmidt 1997) but otherwise morphological differences between the species are unclear. Nuclear data and the different host plants support separation of E. septentrionalis ( Betula) from E. tenuis ( Salix). Since the species is morphologically poorly defined, it is uncertain whether the holotype of septentrionalis is conspecific. The lancet of the holotype of Euura betulae (not reared; lamnium 1.5–1.6 times as long as radix) does not seem to fit with that of E. septentrionalis .

Valvula 3 rather narrow in dorsal view, asymmetrical in lateral view. Dorsal setae of annuli 3–4 shorter than half length of corresponding annulus. Lamnium 1.8–1.9 times as long as radix (based on Schmidt 1997), 2 ( taiganus holotype), 2.1–2.2 (ZMUO.037302).

Type material examined

Holotype Amauronematus septentrionalis

FINLAND – Inari Lapland • ♀; Utsjoki, Outakoski; 69.61° N, 25.98° E; 10 Jun. 1947; A. Saarinen leg.; MZH, http://id.luomus.fi/GL.2776.

Holotype Nematus taiganus

RUSSIA – Magadan oblast • ♀; Magadan; 59.56° N, 150.82° E; 16 Jun. 1963; A. Zhelochovtsev leg.; ZIN, DEI-GISHym89536.

Notes

The holotype of taiganus resembles the holotype of septentrionalis very closely.

Host plants

Betula nana .

Genetics

COI

Based on 10 specimens, maximum within-species distance is 1.98% and the nearest neighbours, diverging by a minimum of 0%, are Euura tota, E. amicula, E. betulae, E. histrio, E. nuorbinjargi, E. rufa, E. striata, and E. tenuis .

Nuclear

Based on 10 specimens, maximum within-species distance is 0.24% (0.49% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 0.36%, is Euura histrio group specimen ZMUO.045035 (perhaps E. striata).

Distribution and material examined

Palaearctic. Specimens studied are from Finland, Norway, Russia, and Sweden.