Bicellaria Macquart

Barták, Miroslav, Plant, Adrian & Kubík, Štěpán, 2013, Species of Bicellaria (Diptera: Hybotidae) from Asia, Zootaxa 3710 (3), pp. 233-256 : 234

Bicellaria Macquart

Bicellaria Macquart, 1823: 155 . Type species: Bicellaria nigra Macquart, 1823: 156 [= spuria (Fallén, 1816) ] (monotypy). Cyrtoma Meigen, 1824: 1 . Type species: Cyrtoma atra Meigen, 1824: 2 , des. Westwood, 1840: 133 [= spuria (Fallén, 1816) ]. Enicopteryx Stephens, 1829: 264 (catalogue name).

Calo Gistel, 1848: VIII, unjustified new name for Cyrtoma . Type species: Cyrtoma atra Meigen, 1824 [= spuria (Fallén, 1816) ].

Diagnosis. Species of the genus are small flies (wing length 1.9~ 4 mm), brown to dull black with black or pale setae (almost exclusively pale in B. chimganensis sp. nov.). Head hemispherical with prominent ocellar triangle bearing one to two pairs of ocellar setae and short proboscis, palpus with one to ~10 setae. Antenna black, pedicel with circlet of setae, ventral ones often elongated, lateral ones elongated in B. longisetosa Chvála, 1991 , third segment with one to several elongate dorsal setae situated on proximal part of the segment ( B. austriaca complex) or on distal part of the segment ( B. dispar Oldenberg, 1920 ) or without seta(e), apical stylus two-segmented. Face sometimes very narrow (about 0.02 mm), even narrower below ( B. vana , B. koreana sp. nov., B. nigra complex), in most species slightly narrowed ventrally, but also broadened ventrally ( B. pilosa Lundbeck, 1910 ). Thorax dull black, more or less arched, conspicuously setose. Acrostichals biserial and distinctly separated from dorsocentrals, setae sometimes long (more than 0.15 mm) but shortened in some species ( B. koreana sp. nov., extremely so in B. dispar ), taxonomically important but overlooked by previous authors is number of setae in intrahumeral and posthumeral areas (i.e., in presutural area laterad from dorsocentrals). Legs slender, at most hind tibia at least slightly swollen apically, usually less distinctly so in females. Fore femur usually with sparse rows of short antero- and posteroventral setae; fore tibia with species-specific ciliation on ventral part in distal third: some species bearing pilosity similar to that of fore basitarsus but absent or very short in other species and posteroventral setae very short, absent or distinctly longer than diameter of tibia in other species (usually short posteroventral setae found in species with long pilosity—typical feature of B. sulcata and B. nigra complexes). Mid femur usually with very short anteroventrals (somewhat longer in B. setitibia sp. nov.) and longer posteroventrals. Mid tibia usually with one to several dorsal pairs of setae situated on basal two-thirds, in B. setitibia sp. nov. with long setae also on apical part. Hind femur usually with two rows of elongate setae anterodorsally and anteroventrally, posteroventrals usually much shorter or (rarely) absent. Hind tibia mostly swollen in males and less so in females, but sometimes almost clavate [ B. stackelbergi , B. sulcata (Zetterstedt, 1842) ] or narrow and not at all swollen [ B. simplicipes (Zetterstedt, 1842) ], hind tibia with long and strong apical setae in B. woodi sp. nov. Wing usually at least slightly darkened, cell dm absent, base of vein M often depigmented, vein A1 reaching (or nearly so) hind wing margin, area between tip of veins Sc and R1 stigma-like darkened. Abdomen elongate and narrow, in males usually darker in dorsal view and lighter in lateral view. A detailed description of the male genitalia was given by Barták and Kubík (2013) and the following presents a more detailed comparison with respect to Asian fauna. Male genitalia usually small (somewhat larger and almost globular in B. globulicauda sp. nov.). Epandrium, cerci and hypoproct usually very similar between species, apparently without useful diagnostic features (except B. globulicauda sp. nov. with swollen epandrium). Hypandrium usually with two processes (absent in B. farkaci sp. nov. or with additional rounded process between processes in one unidentified specimen from Georgia), in most species bearing several moderately long spines near apex, but also long setose along its length ( B. femorata Collin, 1960 , B. japonica Kato, 1971 ). Shape of hypandrial processes very important: in several species processes long and narrow (e.g., B. koreana sp. nov.), or contrastingly short and broad ( B. uvens ), or long and broad ( B. shatalkini sp. nov.). Hypandrium articulates dorsally with symmetrical postgonites (slightly asymmetrical in B. chimganensis sp. nov.), mostly roughly rectangular or trapezoid in lateral view, sometimes short ( B. shatalkini sp. nov.) or elongate ( B. kovalevi sp. nov.), triangular or broadened laterally (narrow in lateral view in B. uvens ), precise shape of postgonites species-specific. Left and right postgonites connected dorsally; middle connected part articulates closely with phallic hooks. Phallus membranous in most species, in B. longisetosa dorsal side sclerotized forming roof-like flat sclerite. The structure of the phallic hooks provides many important differentiating characters. Usually two phallic hooks are developed and sometimes the right one is reduced, although in B. setitibia the left one is reduced (see remarks under the species). Species of B. pilosa -complex have three phallic hooks (left hook bifurcate, extremely so in B. femorata , Fig. 7 ). Female terminal segments with at least 8th sternite nearly always shining (except B. farkaci sp. nov.), and basal part of tergite 8 shining in most species (often also basal parts of tergites 6–7, but dry specimens often hidden under preceding tergites); rarely ( B. amankutanensis sp. nov.) tergites 5–8 and sternites 6–8 also shining.

Figures

FIGURES 1 – 8. Hypandrium (ventral view) and phallus with postgonites (lateral view). 1 – 2. Bicellaria amankutanensis sp. nov. 3 – 4. B. chimganensis sp. nov. 5 – 6. B. farkaci sp. nov. 7 – 8. B. femorata Collin. Scale bars = 0.10 mm.