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.
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 Pacific islands, has vein M beyond the dm—cu crossvein reduced to a faint trace. Anew diaphorine genus from Senegal, Aphasmaphleps, having Phasmaphleps-like venation is described here. The World Catalog of Dolichopodidae (Yang et al. 2006) 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 then being combined to increase depth of field using Helicon Focus v. 4.77 software. Morphological terminology follows Grichanov (2007) and Cumming and Wood (2009). 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 abdominal segment 7. Wing length is measured from the base to the wing apex. Male genitalia were macerated in 10% KOH. Figures showing the male genitalia in lateral 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).
Etymology: The genus name refers to similarity of its wing to that of Phasmaphleps Bickel. Feminine gender.
Type species: Aphasmaphleps bandia sp. n.
Head: Occiput concave; pairs of strong postvertical, strong vertical and strong ocellar setae present; male eyes joined across lower face with anteroventral facets enlarged; postpedicel subtriangular, with dorsoapical arista-like stylus.
Thorax: Mesonotum with little pruinosity; setae black; acrostichals biseriate; 5 dorsocentrals present, with posteriormost pair slightly offset laterally; lower part of proepisternum with pale seta just above coxa, subtended dorsally by shorter seta; upper part of proepisternum with 1 weak white seta; lateral scutellar setae absent.
Legs: Femora without true preapical anterior bristles.
Wing: Costal vein extending beyond tip of R4+5, but not reaching vein M; R4+5 ending not far from wing apex; vein M ending at wing apex; distal parts of R4+5 and M1+2 slightly diverging and slightly convex anteriorly, parallel at apex; dm—cu much shorter than distal part of CuA1.
Abdomen: With short black vestiture; male postabdomen (Fig. 7): tergum and sternum 7 greatly reduced; segment 8 with 2 strong diverging setae which project posteriad; 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.
Remarks. Bickel (2005) has defined 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 R4+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 R4+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 R4+5 and M1+2 (at R4+5 in Phasmaphleps); R4+5 ending before wing apex; vein M ending at wing apex; distal parts of R4+5 and M1+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 antennomeres, modified 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 joined eyes (Figs 8, 9). Nevertheless, 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.
Etymology: The species is named after the type locality.
Head: Frons broad, dark bluish green with weak grey pruinosity; 2 pairs of strong postverticals, 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, subtriangular, flattened laterally, with long dorsoapical arista-like stylus; length ratios of scape to pedicel to postpedicel to stylus (1st and 2nd stylomeres), 7:4:7:10:75; postcranium shining black; postocular setae white except few upper setae, slightly flattened, uniserial; 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 4th 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.
Legs: All coxae and remainder of legs yellow, with only mid and hind coxae brown at base and distalmost tarsomeres of mid and hind legs brown; coxae with pale yellow setae; fore coxa with 3 yellow distolateral setae; mid coxa with pale anterior setae; hind coxa with single brown lateral seta at basal quarter; femora devoid of strong setae; claws and pulvilli on mid and hind tarsi short; fore tibia with only 2 short dorsoapical setae; fore tarsomeres slightly thickened, with pale ventral pad of short dense hairs; 5th tarsomere with slightly enlarged pulvilli and with claws reduced to simple setae; mid femur with 3 fine ventral erect cilia at base, half as long as femur diameter; mid tibia with strong anterodorsal seta at basal ¼, and 3 or 4 apical setae; mid basitarsus with anterior and ventral rows of stiff hairs, which longer than segment diameter; 2nd segment shortened; hind femur with fine posteroventral subapical seta, with somewhat elongated dorsal setulae; hind tibia with 2 short dorsal and 3 or 4 short apical setae. Length ratios of fore femur to tibia to tarsus (segments from first to fifth), 45:42:15:6:6:5:5; same ratios for mid leg, 45:55:30:5:10:7:15; same ratios for hind leg, 50:63:19:19:12:7:6.
Wing: Costal vein reaching half distance between R4+5 and M1+2; R4+5 ending not far from wing apex; vein M ending at wing apex; distal parts of R4+5 and M1+2 slightly diverging and slightly convex anteriorly, parallel at apex; M between crossvein dm—cu and wing apex very weak, foldlike; dm—cu faint; anal vein fold-like; ratio of dm—cu to distal part of CuA1, 1:16; lower calypter yellow with pale setae (mostly broken in unique specimen); halter yellow.
Abdomen: Dull metallic with black vestiture; terga 1 and 2 dull green with copper reflection; remainder terga violet-black; postabdomen (Fig. 7); sterna 5 and 6 weak; sternum 5 concave; sternum 6 reduced; tergum and sternum 7 greatly reduced; male sternum 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.
Measurements (mm): Body length without antennae 1.6, antenna 1.3, wing length 1.6, wing width 0.5.
Holotype: ♂ SENEGAL: Bandia, 16.vi.1980, B. Sigwalt leg., Piège de Malaise (MNHN).
Key to Afrotropical genera of Diaphorinae
1 Costa not extending beyond tip of R4+5; distal vein M gently sinuate or broken or weakened, with distal section often displaced 2
— Costa extending beyond tip of R4+5, usually ending at apex of vein M; vein M unbroken, rarely weakened 5
2 Vein R4+5 ending along distal anterior wing margin, well before wing apex; distal parts of R4+5 and M1+2 strongly diverging 3
— Vein R4+5 ending almost at wing apex; distal parts of R4+5 and M1+2 subparallel, slightly diverging or bowed with respect to each other 4
3 Upper part of proepisternum with 2–4 fine setae; acrostichals usually present; male sternite 8 often with strong projecting setae Asyndetus Loew, 1869
— Upper part of proepisternum usually bare; acrostichals absent or microscopic; male sternite 8 without strong setae Cryptophleps Lichtwardt, 1898
4 Acrostichals biseriate; male antenna very long (⅘ the body length); male fore and mid tarsi modified; male sternite 8 with 2 strong projecting setae Aphasmaphleps gen. n.
— Acrostichals absent; male antenna about as long as head height; male fore and mid tarsi simple; male sternite 8 without strong setae; western Pacific [Phasmaphleps Bickel, 2005]
5 Occiput concave; antennal postpedicel usually pressed laterally, bladelike to subtriangular, with distinct apex and dorsal to dorsoapical arista-like stylus 6
— Occiput convex or flat; antennal postpedicel usually globular, reniform, conoid or budlike, with indistinct apex, or with slender apical projection, and with subapical or apical, rarely dorsal, arista-like stylus inserted sometimes in apical incision 8
6 Hind coxa with external vertical row of 3 or 4 setae decreasing in length ventrally; scape with dorsal setae (bare in some Holarctic species) Argyra Macquart, 1834
— Hind coxa with one external seta at basal quarter; scape bare 7
7 Wing vein M1+2 with rather distinct sinuation at ⅖ of distal part; arista-like stylus dorsal; antennae positioned at upper quarter of head; male segment 7 rather long Urodolichus Lamb, 1922
8 Posterior four femora with anterior subapical seta in both sexes; male frons and face broad 9
— Posterior four femora without distinct anterior subapical seta, at most with stiff hairs; male eyes usually convergent or contiguous above or below antennae 10
9 Antennal pedicel with finger-like projection overlapping postpedicel; male sternite 8 with strong projecting setae Dactylonotus Parent, 1934
— Antennal pedicel without finger-like projection; male sternite 8 without strong setae Nurteria Dyte & Smith, 1980
10 Acrostichal setae absent; female clypeus with four projecting setae; male segment 7 rather long; postgonite prominent, often with a group of pedunculate setae Acropsilus Mik, 1878
— Acrostichals present, biseriate; female clypeus without setae; male segment 7 short; postgonite reduced 11
11 Antennae positioned at middle of head; upper part of proepisternum with 2–4 fine setae; wing usually broadest at basal quarter, with nearly straight R4+5 and M veins Diaphorus Meigen, 1824
— Antennae positioned at upper quarter to third of head; upper part of proepisternum usually bare; wing usually broadest at middle, with convex anteriorly R4+5 and M veins 12
12 Face nearly parallel-sided, subequal in width to frons; male postpedicel budlike, with abruptly drawn-out apex; male sternite 8 with strong projecting setae; hypopygial surstylus and epandrial lobe long and thin; male cercus with long distoventral projection Trigonocera Becker, 1902
— Male eyes convergent or contiguous below antennae; female face distinctly narrowed downwards; male postpedicel globular, reniform, conoid (Chrysotus) or with slender apical projection (Achradocera); male sternite 8 with simple hairs, rarely with short thick setae; surstylus and epandrial lobe broad; male cercus without distoventral projection 13
13 Male postpedicel with slender apical projection bearing apical arista-like stylus, and lower postocular surface of male with many flattened pale setae Achradocera Becker, 1922
— Male postpedicel globular, reniform or conoid with subapical arista-like stylus; lower postocular surface with fine unmodified setae Chrysotus Meigen, 1824
(2) Bickel (1998) considered Acropsilus incertae sedis, rejecting its placement in Peloropeodinae and Grichanov (1998) associated the genus with the Diaphorinae. Yang et al. (2006) followed Negrobov (1991), placing it in the Peloropeodinae.
(3) Nurteria with three known species is an unrevised genus originally described in the Diaphorinae. Numerous undescribed species of the genus from southern Africa share some features with the Sympycninae.
The author expresses sincere gratitude to late Dr Loïc Matile (Paris) for his kindness in furnishing the opportunity to study the collection of his museum and to Dr Vladimir Blagoderov (London) who provided photos of the holotype F. acorensis. Dr Daniel Bickel and Dr Igor Shamshev kindly commented on earlier drafts of the manuscript.