Orthonevra species

Key to the European Orthonevra species with black legs

1 Legs entirely black, or (in some specimens of O. erythrogona View in CoL ) only knees yellowish. ......................... 2

– Legs in large part orange or brown. ............................. ................. Other European Orthonevra View in CoL : O. elegans (Wiedemann, 1822) View in CoL , O. gemmula Violovitsh, 1979 View in CoL , O. geniculata (Meigen, 1830) View in CoL , O. intermedia Lundbeck, 1916 View in CoL and O. stackelbergi Thompson & Torp, 1982 View in CoL

2 Postpedicel short, less than 1.3 times as long as wide. ................................................................................ 3

– Postpedicel elongated, more than 1.3 times as long as wide. ........................................................................ 8

3 Postpedicel orange-brown in part. ............................ 4

– Postpedicel entirely black. ........................................ 7

4 Sternite I shiny, not contrasting with sternites II–IV; female: tergite V without incision in the middle; male terminalia: surstyli broadened in basal half ( Fig. 5A View Fig ). ..... 5

– Sternite I heavily pollinose, contrasting with shiny sternites II–IV; female: tergite V with incision; male terminalia: surstyli slender. ....................................... 6

5 Postpedicel black with a restricted orange-brown area basoventrally ( Fig. 3A View Fig ); wing vein M 1 recessive ( Figs 7A, 7B View Fig ); slightly larger and more pitch black species; wing venation usually pitch black; males: scutum at least with some black hairs on central disc (best seen in posterior view), often extensively black haired; vertex with black hairs; male terminalia: phallus in shape of broad cylindrical cavity ( Fig. 5C View Fig ) with anterodorsal hook-shaped appendix in lateral view long and slender ( Fig. 5A View Fig ), postgonites with quadrate tip posterodorsally, extending beyond tip of phallus ( Fig. 5A View Fig ) and without hook-shaped extension anteroventrally ( Fig. 5B View Fig ); mostly in Western Europe. .................................. .... O. atlantica Żóralski & Van de Meutter sp. nov.

– Postpedicel with orange-brown area extending more to the tip ( Fig. 3B View Fig ); wing vein M 1 less or non-recessive ( Figs 7F, 7G View Fig ); slightly smaller and more greyish species; wing venation usually grey-brown to black; males: scutum and vertex with yellow hairs; male terminalia: phallus flattened laterally ( Fig. 5F View Fig ) and with anterodorsal hook-shaped appendix in lateral view broader and shorter ( Figs 5D View Fig ), postgonites with rounder tip posterodorsally, not extending beyond tip of phallus ( Fig. 5D View Fig ) and with visible hook-shaped extension anteroventrally ( Fig. 5E View Fig ); Central Europe into Greece and Transcaucasia. ................................. O. brevicornis ( Loew, 1843) View in CoL

6 Body with longer hairs (RlCARTF et al. 2022: fig. 4); wing vein M 1 recessive; eye without or with very short scattered hairs; katepisternum with third patch of hairs below dorsal patch in such way that dorsal and ventral patches might be connected or almost so; hind femur with black, sometimes spiny, black hairs ventrally; male terminalia: postognites slightly asymmetric, bearing a spur on inner side (RlCARTF et al. 2022: fig. 7); Western Europe. .......................................................... .................. O. arcana Ricarte & Nedeljković, 2022 View in CoL

– Body with shorter hairs (RlCARTF et al. 2022: fig. 11); wing vein M 1 less or non-recessive; eye virtually bare; katepisternum with two separate patches of hairs, one dorsal and another ventral; hind femur entirely white pilose, at most with some scattered black hairs ventrally; male terminalia: postgonites extremely asymmetric and twisted (RlCARTF et al. 2022: fig. 14, STACKFLBFRG 1953: fig. 13); Central Europe, Asia. ........................... ............................................. O. incisa ( Loew, 1843) View in CoL

7 Hairs on central disc of mesoscutum usually with mixed black and pale hairs; slightly larger species; wing vein M 1 more recessive; male terminalia: anterodorsal appendix of phallus in lateral view like bird’s head, but variable in shape; postgonites long (VUIlĉ 1999: fig. 38). The Alps, west to Pyrenees, Cantabrian Mts. and Massif Central. ...................... O. tristis (Loew, 1871) View in CoL

– Hairs on central disc of mesoscutum usually predominantly black; slightly smaller species; wing vein M 1 less recessive (VUIlĉ 1999: fig. 31); male terminalia: anterodorsal appendix of phallus in lateral view shorter, hook-shaped; postgonites shorter and broader (VU- Ilĉ 1999: fig. 36). The Alps, east to Sudetes, Carpathi- an and Balkan Mts. .............. O. montana Vujić, 1999 View in CoL

8 Postpedicel narrow, bar-shaped, rectangular (LoFw 1843: fig. 10; BAŇKowsKA 1963: fig. 451); sternite I pollinose; male terminalia: postgonites enlarged, in lateral view extending far beyond tip of phallus (VUIlĉ 1999: fig. 25). Southern Europe. ..................... ........................................ O. frontalis ( Loew, 1843) View in CoL

– Postpedicel of other shape. ....................................... 9

9 Postpedicel more than 3× as long as wide. .................. .................................... O. fumipennis ( Loew, 1843) View in CoL

– Postpedicel less than 3× as long as wide. ............... 10

10 Postpedicel more than or about 2× as long as wide, tapering towards apex, with pointed tip. ................ 11

– Postpedicel less than 1.5× as long as wide, rounded at tip. Male unknown. ......... O. plumbago (Loew, 1840)

11 Postpedicel partly orange; legs black; female: tergite IV with denticle; male terminalia: anterodorsal appendix of phallus in lateral view like duck head (STACKFL- BFRG 1953: fig. 17.4; VloLovlTsH 1979: fig. 1; VUIlĉ 1999: fig. 23). ..................... O. nobilis (Fallén, 1817)

– Postpedicel black; knees usually slightly lightened; female: tergite IV without denticle; male terminalia: anterodorsal appendix of phallus in lateral view like snake (STACKFLBFRG 1953: fig. 3.3), phallus extremely long (VloLovlTsH 1979: fig. 6). ................................... ................................. O. erythrogona (Malm, 1863) View in CoL