Meuffelsia, a New Genus of Long-Legged Flies from South Africa, with a Key to Afrotropical Peloropeodine and Allied Genera (Diptera: Dolichopodidae)

ABSTRACT The genus Meuffelsia Grichanov, gen. n. is described from South Africa to accommodate two new species, M. erasmusorum Grichanov. sp. n. and M. manningi Grichanov, sp. n. The new genus has been placed in the subfamily Peloropeodinae, and is considered close to the genera Micromorphus and Peloropeodes. Brief information on the habitat of M. erasmusorum is provided; in general, representatives of the new genus seem to prefer mesic riparian environments. A key to Afrotropical peloropeodine and allied genera of long-legged flies is compiled, and characters of the new genus are discussed.


INTRODUCTION
The 'World catalog of Dolichopodidae' (Yang et al. 2006) lists 15 genera in the subfamily Peloropeodinae, which is still poorly defined (Grichanov 2000). Several unrevised genera of uncertain taxonomic position included in the subfamily blur its border with Sympycninae. There are two relatively well-defined and distinctive genera (Peloropeodes Wheeler, 1890 andMicromorphus Mik, 1878) that are distributed worldwide, including the Afrotropics. These genera differ from other members of the subfamily, first of all, in having sessile hypopygia.
A male and a female of a peculiar peloropeodine species have been collected using a Malaise trap at the Sanyati Nature Farm near Loewsburg, KwaZulu-Natal, South Africa. A study of published descriptions (Parent 1938;Robinson & Vockeroth 1981;Meuffels & Grootaert 1987, 1997a, b, 2004Bickel 1992Bickel , 1999Bickel , 2004Runyon & Hurley 2003;Negrobov 2003;Grootaert 2006, etc.) has been unsuccessful in seeking an appropriate genus for this species. Subsequent treatment of collections from the Natal Musem led to discovery of two more specimens of the same species, and of a series consisting of one male accompanied by three females that represent another close species. Both species belong to a new genus that shares features of Micromorphus and Peloropeodes, but their inclusion in either of the latter genera would diffuse the generic concepts of both taxa. This paper offers a description of a new genus along with a key to all Afrotropical peloropeodine and sympycnine genera, with three species groups of Sympycnus and two genera previously included into the subfamily Peloropeodinae.

MATERIAL AND METHODS
The left and right lateral views of the hypopygium, or male genital capsule, are illustrated for the new species. In describing the hypopygium, 'dorsal' and 'ventral' refer to the morphological position prior to rotation and flexion. Thus, in figures showing a lateral view of the hypopygium, the top of the page is morphologically ventral, while the bottom is dorsal. Morphological terminology follows Robinson and Vockeroth (1981), Stuckenberg (1999), and Grichanov (2007).
All studied material is housed in the collection of the Natal Museum, Pietermaritzburg, South Africa (NMSA). TAXONOMY Subfamily Peloropeodinae Robinson, 1970 Genus Meuffelsia Grichanov, gen. n. Etymology: The genus is named for the famous Dutch researcher of the Dolichopodidae, Henk Meuffels. Gender feminine. Type species: Meuffelsia erasmusorum Grichanov, sp. n. Diagnosis: The generic diagnosis is based on the two very close included species, and lists features considered to be of generic importance.
Length less than 2.0 mm; body dark, with dark setae; dorsal part of postcranium slightly concave; face without setae, relatively broad, slightly narrowed downward; pedicel globular; postpedicel small, subtriangular; stylus dorsoapical; labella with 6 pseudotracheae; posterior part of mesonotum distinctly flattened and slightly depressed; acrostichals biserial; 6 dorsocentrals; scutellum with 2 strong bristles and 2 minute adjacent lateral hairs; fore and mid coxae with anterior and apical cilia; hind coxa with  Grichanov, sp. n., general habitus of the holotype in alcohol before dissection. 1 seta at middle; legs simple, with simple setae; mid and hind femora with strong anterior subapical seta; hind tarsus simple; wing nearly as long as body, relatively broad; m-cu short; segment 7 small, with tergum broad and sternum reduced; segment 8 large; hypopygial foramen left lateral; hypopygium with rounded-ovate cercus; hypandrium long and thick, asymmetrical, fused at base to epandrium; ventral surface of epandrium bare; surstyli asymmetrical, with left dorsal arm shorter or longer than right one, both broad, bearing a few short setae, and ventral arms of surstyli subequal in length, thin, directed ventrad, bearing a few short setae at apex; oviscapt with tergum 9+10 split medially into two arcuate narrow hemitergites, each bearing 4 short black acanthophorites; female cercus short, widened distad; anal plate broad, wider than long. Grichanov, sp. n. Figs 1-6 Etymology: The species is named in honour of Thea and Cobus Erasmus, on whose property the types were collected. Description: Colour (dry paratypes): Frons and face weakly shining bronze, brownish pollinose. Palpus and proboscis blackish brown; thorax bluish black; legs with coxae, femora and tarsi from apex of basitarsus mainly light brown; other podomeres mainly reddish yellow; abdomen black with brown sternites. Male. Head: Frons and face with black ground colour. One strong but short postvertical seta positioned far from postocular setal row; postocular setae all dark; 1 or 2 upper and 1 lower setae slightly longer than the others. Face under antennae 2× as wide as height of postpedicel. Antenna black, slightly longer than head height. Scape small, vase-like, with projecting inner angle forming distal denticle; pedicel larger, globular, with ring of short setulae and elongate apicodorsal seta; postpedicel subtriangular, as long as high at base, densely haired; stylus inserted dorsally at 2/3 from postpedicel base, 2× as long as main segments of antenna combined, shortly pubescent, with short thick segment 1 and filiform segment 2. Ratio of lengths of scape to pedicel to postpedicel to stylomere 1 to stylomere 2, 3:3:4:1:20. Palpus and proboscis yellow-brown, palpus subtriangular, with dark pubescence and dark short bristle. Thorax: With dark bristles, mesonotum blackish brown, pleura dark brown. One long and 1 short intra-alar, 1 humeral, 1 supra-alar, 2 notopleurals, 1 sutural, 1 presutural; 6 (2+4) dorsocentrals, with first slightly shorter and last slightly longer than others; 5th seta not shifted towards lateral margin; 6 or 7 pairs of biserial acrostichals extending to well-developed posterior mesonotal flattening. Upper propleuron without setae; proepisternum with 1 strong seta and 1 short hair above fore coxa. Legs: Mainly dirty yellow; mid and hind coxae, hind femur and apical segments of all tarsi distinctly brownish. Fore and mid coxae with dark anterior and apical cilia; hind coxa with 1 black bristle at middle. Fore leg without extraordinary setae; fore femur with just 1 or 2 short posteroventrals at apex; fore tibia simple, without strong setae; fore tarsus simple, with ordinary setulae. Length ratio of fore femur to tibia to tarsus (segments from first to fifth), 19:23:10:4:3:3:4. Mid femur simple, bearing 1 strong anterior subapical bristle and 1 fine posteroventral seta; mid tibia simple, with 1 very strong anterodorsal and 1 fine posterodorsal setae at basal third and 3 apical setae; no ventral setae; mid tarsus simple; segments 1-4 each with circlet of short apical spinules. Length ratio of mid femur to tibia to tarsus (segments from first to fifth), 30:31:14:5:4:3:4. Hind femur with 1 strong anterior subapical seta; hind tibia simple, with 1 strong anterior at basal 1/3, and 3 short posterodorsal, 2 or 3 very short ventral, 3 simple short apical setae, with only anterior apical seta somewhat longer, without strong dorsal subapical seta; hind tarsus simple; hind basitarsus with 1 short basoventral and 1 or 2 short apicoventral setae, with very small basal tooth posteriorly directed towards apex of hind tibia. Length ratio of hind femur to tibia to tarsus (segments from first to fifth), 35:35:15:14:6:4:5.  Habitat: The type specimens from Sanyati Nature Farm were collected in the primarily indigenous riverine bush (Fig. 7) As reported by Dr R.M. Miller, the collecting site of the other two paratypes was most probably along the small river that runs down the valley with indigenous forest. Grichanov,sp. n. Figs 8,9 Etymology: The species is named after J. Manning, who collected the type series. Description: Male. Similar to M. erasmusorum sp. n. in all respects except as noted.
Epandrium globular, asymmetrical, distinctly (1.5×) longer than high, as wide as high; hypopygium with rounded-ovate densely haired cercus; hypandrium mostly concealed, asymmetrical, slightly shifted towards left side, deeply bifurcated from its midlength (ventral view), with broad, apically pointed lobes almost equal in length and shape; aedeagus expanded at apex, with adjacent long thin process; ventral surface of epandrium bare; distal epandrial lobes short and broad, bare, without projections; surstyli

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Comparison: The two described species can hardly be distinguished by external morphology. Nevertheless, wing vein m-cu is located slightly closer to the wing base in M. erasmusorum than in M. manningi; therefore, wing vein ratios differ somewhat in both males and females of the two species. The species are easily distinguished by hypopygium morphology. The hypandrium is deeply bifurcated, with almost equal lobes in M. manningi, but with only a large triangular lobe on the right side of the main arm in M. erasmusorum. The surstyli are rather distinct in their shape and setation pattern, and their ventral arm in M. manningi is peculiar in bearing several long and strong pedunculate setae on the basal half. The latter species also has a somewhat more elongated epandrium and smaller cercus than M. erasmusorum. It is also worth noting that the left dorsal arm is shorter than the right one in M. erasmusorum, and vice versa in M. manningi.
Key to Afrotropical peloropeodine and allied genera and species groups Regarding Afrotropical Peloropeodinae and Sympycninae, the 'World catalog of Dolichopodidae' includes 11 genera, some of which should be excluded from the list (Grichanov 1998(Grichanov , 2008a. This key does not reflect phylogenetic relations of included taxa, being compiled for practical use only. Species groups in the genus Sympycnus follow Grichanov (2008b). 11 Two rather than one postverticals; strong ventral subapical seta on hind tibia; wing veins R 4+5 and M 1+2 slightly diverging rather than parallel; strongly oblique crossvein m-cu forming acute (ca 60°) angle with CuA 1 ; mid femur with ventral bristles in basal part; male wing costa with long and thick stigma beyond R 1 ; epandrial foramen mostly middorsal . The following character states places Meuffelsia in the Peloropeodinae (see Yang et al. 2006): Occiput convex backward. Vertex nearly flat. Upper occiput slightly concave, verticals located nearly at level of lateral ocellus; 1 short postvertical. Postocular bristles onerowed. Eyes with tiny hairs. Male eyes separated on face; male face distinctly narrowing downward. Mesonotum with flat mid-posterior slope. Propleuron sparsely haired, with 1 bristle on lower portion. Mid and hind femora with 1 anterior preapical bristle. Hind coxa with 1 outer bristle at middle. Anal cell present; anal vein present as a short fold. Male abdominal tergite 7 short triangular, without hairs and bristles; sternite 7 reduced. Male genitalia relatively large and mostly exposed; surstylus well developed; epandrial lateral lobe distinct; hypandrium long.
The following character states are common to Meuffelsia, Afrotropical Micromorphus and Peloropeodes (after Grichanov 2000): Antenna slightly longer than head height. Scape small, bare, vase-like, with slightly projecting inner apex. Stylus dorsal. Palpus and proboscis short, haired; palpus with one black seta. Pseudotracheae symmetrically sclerotised. One strong vertical seta, half as long as head height; 2 strong ocellar setae of the same length with additional pair of short hairs posteriorly. Postocular setae in one row. Mesonotum distinctly flattened in front of scutellum. Mesonotum with 1 humeral, 1 posthumeral, 2 notopleural, 1 presutural, 1 sutural, 2 intra-alar and 1 supra-alar setae, 1 strong propleural seta. Scutellum with 2 strong setae, with or without very short lateral hairs. Fore tibia without major setae. Hind coxa with 1 black external seta. Mid and hind femora with 1 anterior subapical seta. Mid tarsomeres 1-4 with short apicoventral spinules. Wing costa with 2 strong bristles before humeral crossvein; upper seta longer than lower. Anal lobe long and narrow; anal vein fold-like; alula undeveloped; anal angle obtuse or absent.
Meuffelsia shares with Micromorphus such characters as simple legs, no strong dorsal seta on antennal pedicel, and distal part of CuA 1 being 4-5 times longer than m-cu. Nevertheless, Micromorphus shows striking differences to Meuffelsia: no acrostichals and basal denticle on hind basitarsus; dorsal and ventral subapical setae on hind tibia, 1 strong and 1 hair-like intra-alar setae; setose epandrial lobes at base and at apex of ventral epandrial surface; and symmetrical surstyli. Meuffelsia shares with examined Afrotropical and European species of Peloropeodes such characters as: presence of two rows of acrostichals; well developed segment 7 in males; and usually asymmetrical hypopygium. Nevertheless, Peloropeodes differs in many morphological characters: antennal pedicel with strong dorsal seta; postpedicel usually much larger than pedicel; male mid coxa with apical spine of glued cilia; hind tibia with 1 stronger subapical dorsal seta, slightly longer than diameter of tibia; various podomeres, especially on fore leg, often modified, bearing long setae or cilia; and fore tarsomere 5 always modified, with enlarged asymmetrical claws.
The combination of character states is distinctive to Meuffelsia but any of them may also occur in other Peloropeodinae. However, the postabdomen morphology is very remarkable for the genus, and the unusual male surstylus shape has not yet been described in other genera of the subfamily.