Aphasmaphleps, a New Genus of Long-Legged Flies from Senegal, with a Key to the Genera of Afrotropical Diaphorinae (Diptera: Dolichopodidae)

ABSTRACT The genus Aphasmaphleps Grichanov, gen. n. is described from Senegal to accommodate a new species, A. bandia sp. n. The new genus has been placed in the subfamily Diaphorinae and is considered close to the genus Phasmaphleps Bickel, 2005. A key to Afrotropical diaphorine genera of long-legged flies is compiled, and characters of the new genus are discussed.


INTRODUCTION
The subfamily Diaphorinae has a mainly stable wing venation throughout the subfamily, with completely developed major veins. However, two genera, Asyndetus Loew, 1869, and Cryptophleps Lichtwardt, 1898, are characterized by vein M being distinctly weakened or broken, and in the latter genus usually also having crossvein dm-cu absent. Monotypic Phasmaphleps Bickel, 2005, which is widespread across the western dm-cu crossvein reduced to a faint trace. A new diaphorine genus from Senegal, Aphasmaphleps, having Phasmaphleps-like venation is described here. The World Catalog of Dolichopodidae  lists 18 genera in the subfamily Diaphorinae, and many of them are found in the Afrotropics.
A key to regional genera of Diaphorinae is also presented.

MATERIAL AND METHODS
Aphasmaphleps bandia sp. n. was studied and illustrated with a Zeiss Discovery V-12 stereomicroscope and an AxioCam MRc5 camera. The holotype Falbouria acorensis (Parent, 1933) was photographed by Vladimir Blagoderov in the Sackler Biological Imaging Lab at the Natural History Museum, London (NHML) using a Zeiss Stemi V11 stereomicroscope with a Canon EOS 450D camera attached, the resulting images The relative lengths of the podomeres should be regarded as representative ratios and not measurements. Body length is measured from the base of the antenna to the tip of view are oriented as they appear on the intact specimen, with the morphologically ventral surface of the genitalia facing up, dorsal surface down, anterior end facing right and posterior end facing left.
The holotype of the new species is housed at the Museum of Natural History, Paris (MNHN). Abdomen hypopygial foramen left lateral; epandrium circular with phallus following curvature of epandrium; epandrial lobe with 2 apical setae; surstylus digitiform; postgonite present; cercus short, rounded.
Phasmaphleps by a complex of characters, most of which are met in either Asyndetus or Cryptophleps. The following characters of his new genus have not been observed in the latter two genera: postpedicel with apical arista-like stylus; vein R 4+5 ending near wing apex; vein M beyond crossvein dm-cu becoming a trace, and continuing as a faint fold to just behind wing apex; vein R 4+5 and trace vein M bowed with respect to each other; male cercus elongate with strong distal setae. Aphasmaphleps has dorsoapical arista-like stylus and rounded male cercus (the characters being not rare in Asyndetus and Cryptophleps), strongly differing from these genera in wing venation. The latter in the new genus is most similar to the venation of Phasmaphleps, differing in costal vein reaching half distance between R 4+5 and M 1+2 (at R 4+5 in Phasmaphleps); R 4+5 ending before wing apex; vein M ending at wing apex; distal parts of R 4+5 and M 1+2 slightly diverging and slightly convex anteriorly, parallel at apex. In addition, Aphasmaphleps differs from Phasmaphleps in the presence of one proepisternal seta and biseriate acrostichals (absent in Phasmaphleps), elongate vs short vs simple male fore and mid tarsi, two projecting setae on male segment 8 (absent in Phasmaphleps), and median (Diaphorus-like) position of antennae (at the upper third of head in Phasmaphleps, Asyndetus and Cryptophleps). It is worth noting that the genus Falbouria Dyte, 1980 (nom. n. for Balfouria Parent, 1933) was described from Azores by a male with antennae positioned at middle of head right above Falbouria has normal wing venation, quite bristly legs including strong anterior preapicals on mid and hind femora, short antenna and simple tarsi (Parent 1933). The very long antenna (4/5 the body length) of A. bandia sp. n. is a quite unusual apomorphy in the Diaphorinae (a male secondary sexual character?). The complex of characters supports the generic status of the Aphasmaphleps.

sp. n.
Etymology: The species is named after the type locality. Description: Male. Head verticals, one pair of strong vertical and one pair of strong ocellar setae present; face present as narrow silvery white triangle beneath antennae; eyes (shrunken) joined across lower face with anteroventral facets enlarged; antenna mainly brown, positioned at middle of head; scape mostly pale brownish except dorsal surface, slightly swollen; pedicel with circlet of short setae, with one longish dorsal seta; postpedicel pale at base, A. bandia scape to pedicel to postpedicel to stylus (1 st and 2 nd palpus and proboscis small; palpus black with short black apical seta.
Thorax: Mesonotum and pleura entirely dark metallic bluish green with little pruinosity; setae black; acrostichals in two irregular rows; 5 pairs of dorsocentrals present of approximately equal length except 4 th pair shortened, with posteriormost pair slightly offset laterally; upper part of proepisternum with 1 weak white seta; lower part of proepisternum with pale seta just above coxa, subtended dorsally by shorter seta; one pair of scutellar setae strong, lateral scutellars absent.
Abdomen: Dull metallic with black vestiture; terga 1 and 2 dull green with copper resternum 8 ovate, with 2 strong diverging bristles which project posteriad, and covering left lateral hypopygial foramen; epandrium black with brown surstylus and cercus, circular with thin phallus following curvature of epandrium; hypandrium forming hood over phallus; epandrial lobe small, with 2 strong apical setae and 1 short seta at base; surstylus digitiform, with broader ventral arm and narrow dorsal arm, each with 3 or 4 dorsal setae decreasing in length distad; postgonite swollen at base, with 2 long narrow hooks; cercus short rounded, with strong setae.