Physocephala Schiner, 1861

Stuke, Jens-Hermann, 2016, Taxonomic notes on Western Palaearctic Conopidae (Diptera), Zootaxa 4178 (4), pp. 521-534 : 526-527

Key to the Western Palaearctic species of Physocephala Schiner, 1861

1 Anepimeron completely but lightly dusted, without hairs or bristles (except biguttata , which has obviously long hairs); frons often with distinct black or brown markings; gena brown to black and usually darker than rest of face (although texana can have a more or less light gena); basal aristomere is usually distinct and well developed ( biguttata has a less well developed basal aristomere); basal flagellomere ventrally with a distinct demarcated membranous area; wing usually completely covered with microtrichia with the exception of cubital cell cup, which is more or less without microtrichia................... 2

- Anepimeron shining, and with black hairs or bristles (these may be broken off); frons usually unicolorous, at most with only obscure markings or sometimes more or less completely black in melanistic specimens; gena not usually darker than rest of face ( pusilla can have a more or less dark face); basal aristomere usually hard to detect, if present at all; basal flagellomere ventrally has at most only an indistinctly demarcated membranous area; wing completely covered with microtrichia, or basal medial and basal radial cells without microtrichia........................................................... 5

2 Face with obvious black central keel; no broad stripe of grey dusting adjacent to posterior margin of eye; parafacia at most only very narrowly silver dusted; thorax usually completely black with the exception of the postpronotum, which can be reddish brown; no band of dense dusting reaching from mid coxa to notopleuron, side of thorax often more or less completely bare of dusting; anterior margin of radial cell r4+5 completely brown; calypters can be completely dark brown but at least with a dark brown margin....................................................................................... 3

- Face without black central keel; obvious stripe of grey to silver dusting adjacent to posterior margin of eye; parafacia may be broadly silver dusted; thorax variable reddish brown, and always with an orange-brown scutellum; dense, often silvery dusting at least on the katepisternum and often much more extensively on side of thorax; anterior margin of radial cell r4+5 at least partly hyaline ( texana can have a complete brown anterior margin); calypter completely yellowish white to light brown... 4

3 Black facial stripe not forked ventrally, not extending ventrally downwards at sides of facial grooves; antenna at least partly black; proboscis uniformly blackish; cell cup usually completely without microtrichia; hind edges of tergites 3-5 with wide, indistinctly delimited dust bands which are clearly broader in the middle..................... P. rufipes ( Fabricius, 1781)

- Black facial stripe deeply and broadly forked ventrally, extending downwards on both sides for almost the entire length of the facial grooves; antenna orange to orange-brown; proboscis becoming lighter brown to orange distally and ending in a blackish labellum; cell cup entirely or almost entirely covered with microtrichia; hind edges of tergites 3-5 with narrow, clearly delimited dust bands of even width......................................................... P. nigra ( De Geer, 1776)

4 Mediotergite and anepimeron with distinct long hairs; long haired species, e. g. hairs on the mesoscutum about as long as scape; antenna black; fore margin of wing black to blackish brown tinged, r2+3 completely black; veins of the wing black to dark brown; proboscis completely black; endemic to the Canary Islands....................... P. biguttata Röder, 1883

- Mediotergite and anepimeron without hairs; short haired species, e. g. hairs on the mesoscutum less than ¼ as long as scape; antenna more or less orange-brown; fore margin of wing light brown, r2+3 with a more or less distinct hyaline spot apically; at least subcostal vein Sc yellow brown; proboscis more or less orange-brown; introduced Nearctic species, so far known only from Ukraine................................................................... P. texana ( Williston, 1882)

5 Hind coxa not dusted at all or at least not more densely dusted than middle and fore coxae; pleura usually without dense dusting; if there is a dusting stripe, it begins dorsal to the katepisternum at a point clearly above the middle coxa, and becomes narrower before reaching the notopleuron; typically, mediotergite dorsally without dense dusting which connects the dense dusted spots on the katatergites; arista three-segmented; basal segment usually small but well developed and only occasional hard to detect when retracted into the basal flagellomere; wing characteristically with a distinct, dark foremarginal band; costal cell c and subcostal cell sc always hyaline, and obviously lighter than base of cell r2+3; subcostal vein Sc yellowish brown and obviously lighter than the dark brown radial vein R2+3; radial cell r2+3 usually hyaline distally, with an isolated spot around vein R4+5+M......................................................................... P. vittata ( Fabricius, 1794)

- Hind coxa distinctly more densely dusted than middle and fore coxae; pleura always with an obvious dusting stripe running from the middle coxa and usually reaching the notopleuron without becoming narrower (although in vaginalis it becomes distinctly narrower); typically, mediotergite dorsally with dense dusting which connects the dense dusted spots on the katatergites; arista two-segmented, basal aristomere not developed (except variegata , which has a three-segmented arista) wing usually with different colouration pattern......................................................................... 6

6 Dusting stripe on pleura becoming narrower dorsally; female: theca obviously elongated ( Stuke & Standfuss 2007: Fig 11)................................................................................ P. vaginalis ( Rondani, 1865)

- Dusting stripe on pleura reaching the notopleuron broadly, not becoming narrower dorsally; female: theca not elongated... 7

7 Parafacia completely silver-white dusted; blackish foremarginal band on wing reduced, not reaching beyond radial vein R4+5, and radial cell r2+3 at most dark basally; basal medial cell bm and basal radial cell br almost without microtrichia, discal medial cell dm more or less without microtrichia; arista three-segmented, basal segment usually small but well developed and only occasionally hard to detect when retracted into the basal flagellomere...................... P. variegata ( Meigen, 1824)

- Parafacia at most very narrowly dusted at eye margin; blackish foremarginal band on wing usually broader (although antiqua can have a reduced blackish wing margin similar to P. variegata ); wing cells completely covered with microtrichia (except P. antiqua , which has at least cell br without microtrichia); arista two-segmented, basal aristomere not developed.......... 8

8 Basal radial cell br completely without microtrichia, or in darker winged male specimens at least with a central stripe lacking microtrichia; subcostal cell sc usually distinctly lighter than radial cell r2+3; subcostal vein Sc usually as dark as R2+3; wing pattern very variable but usually more restricted; in less well marked specimens the dark pattern is restricted to a small black band between subcosta Sc and radial vein R4+5, and cell r2+3 is only basally darkened; if base of cubital cell cua1 is not hyaline then there is no distinct border between the dark base and the hyaline tip; if cell dm is dark brown then in most cases it is distinctly lighter than cell r2+3............................................................ P. antiqua ( Wiedemann, 1830)

- Basal radial cell br completely covered with microtrichia; either subcostal cell sc blackish like radial cell r2+3, and subcostal vein Sc dark like the radial vein R2+3,or subcostal cell sc hyaline and distinctly lighter than radial cell r2+3, and subcostal vein Sc distinctly lighter than the dark brown to black radial vein R2+3; wing pattern very variable, but never as restricted as antiqua can be; the base of cubital cell cua1 is uniformly blackish and almost always has a distinct border alongside the hyaline apical part; cell dm in most specimens is as brown to blackish as cell r2+3................................................... 9

9 Costal cell c and subcostal cell sc blackish like the adjacent cells; subcostal vein Sc black to dark brown like radius R2+3; radial cell r2+3 usually hyaline apically; base of cubital cell cua1 usually blackish; specimens with more or less black femora are frequent........................................................................... P. pusilla ( Meigen, 1804)

- Costal cell and subcostal cell more or less hyaline, obvious lighter than the dark brown adjacent cells; subcostal vein Sc light yellow, obviously lighter than radius R2+3; radial cell r2+3 typically completely black; base of cubital cell cua1 hyaline in most specimens; legs usually completely orange-brown................................... P. chrysorrhoea ( Meigen, 1824)