Cheilosia barbafacies Vujic & Radenkovic

Vujic, Ante, Radenkovic, Snezana, Trifunov, Sonja & Nikolic, Tijana, 2013, Key for European species of the Cheilosia proxima group (Diptera, Syrphidae) with a description of a new species, ZooKeys 269, pp. 33-50 : 37-44

Cheilosia barbafacies Vujic & Radenkovic sp. n. Figs 1A2A, 2B4A, 4B5-78A, 8C9-1112A, 12B

Cheilosia honesta of Šimić, 1987 (in part).

Cheilosia pascuorum of Vujić, 1996 (in part).

Type-locality.

MONTENEGRO: Durmitor, Škrčko-Sušički basen, 43˚11'7"N, 19˚3'28"E, broad-leaf forest, 25 June 1995, A. Vujić leg.

Type-specimen:

Holotype ♂, in excellent condition. MONTENEGRO. Original label: "Durmitor YU / Skakala 25.06.'95. / leg. Vujić.” 43°10'16"N; 18˚59'56"E (FSUNS 05768).

Paratypes, in excellent condition. MONTENEGRO: ♂ Original label: "007. Durmitor / Skrcka jezera / 5.07.1983." 43°8'8"N; 19°0'56"E (published in Šimić (1987) as Cheilosia honesta ) (FSUNS 05758); ♂ Original label: "199 G. Durmitor / Luke / 8.07.1991. YU." 43°7'37"N; 19°0'5"E (published in Vujić (1996) as Cheilosia pascuorum ) (FSUNS 05759); ♂ Original label: "199 H. Durmitor / Luke / 9.07.1991. YU." 43°7'37"N; 19°0'5"E (FSUNS 05763); 3♂ Original label: "199 H. Kanjon Susice / 9.07.1991. YU." 43°12'41"N; 18°59'44"E (FSUNS 05760, 05761, 05766); ♂ Original label: "Dur mitor 8.07.92. / Skrcko Zdrijelo YU / leg.Vujic. " 43°7'7"N; 19°0'53"E (FSUNS 05765); ♂ Original label: "Durmitor 2.07.93. / ka Prutasu YU / leg. Radnovic S." 43°10'16"N; 18°59'56"E (FSUNS 05764); ♂ Original label: "Durmitor 1.6.1994 / KanjonSusice YU / leg. Vujic." 43°12'41"N; 18°59'44"E (FSUNS 05770); ♂ Original label: "Durmitor YU / Skakala 6.7.1994. / leg. Vujic." 43°11'16"N; 19°0'21"E (FSUNS 05767); ♂ Original label: "Durmitor 30.06.93. / Skrčko jezero YU / leg. Radnovic S." 43°8'8"N; 19°0'56"E (FSUNS 05762); ♂ (FSUNS 05771) ♀ (FSUNS 05769) Original label: "Durmitor 25-26.5.96. / Susica-Skrke YU / leg. Vujic". 43°11'7"N; 19°0'28"E. BOSNIA-HERZEGOVINA: ♂ Original label: "1613 Bosna / Jahorina / 14.05.1989." 43°42'25"N; 18°34'13"E (published in Vujić (1996) as Cheilosia pascuorum ) (FSUNS 05757).

Description.

MALE (Figs 1A, 2A, 2B, 4A, 4B, 5, 6C, 8A, 8C, 9A, 11A, 12A, 12B).

Head: Face with long, predominantly pale hairs, central prominence rounded (Fig. 5); orbital stripe with short, pale hairs. Frontal triangle small, undusted, covered with black hairs; eye contiguity longer than frontal triangle (Fig. 6C). Eyes completely covered with greyish hairs. Occiput narrow, white-grey dusted. Antennae dark, third antennal segment from dark-brown to reddish; arista bare and short (Fig. 11A). Clypeus dusted.

Thorax: Scutum with dark-olive shine, laterally slightly dusted, covered with long, pale and black hairs (Fig. 9A); central disc shining, with fine puncturation. Scutellum covered with long hairs and numerous longer black hairs on posterior margin (Fig. 9A). Pleurae dusted, covered with predominantly pale hairs mixed with black hairs on anepisternum and anepimeron; katepisternum continuosly pilose. Wing brownish, with dark veins, completely covered with microtrichia; vein M1 meeting vein R4+5 at an obtuse angle (Fig. 7: x). Calypters yellowish-grey. Haltere yellowish-grey with dark capitulum. Legs dark, except pale apex of femora, basal 1/3-1/4 and apical 1/5-1/6 of tibiae and ventral surface of tarsi on fore and middle legs; hairs on legs predominately pale mixed with black.

Abdomen: Tergites shining, except the whole tergite 2 and dull central area on tergites 2 and 3, which extends from anterior margin of tergite 2 to basal 6/7 of tergite 3, leaving the posterior margin of tergite 3 shining; tergites covered with erected, pale hairs, except few black hairs on posterior half of tergite 4 and on pregenital segments. Sternites grey dusted covered with pale hairs.

Genitalia: Dorsal lobe of gonostylus broad basally (Fig. 8A), without distinct dorsolateral extension (Figs 1A, 2A, 2B), present in Cheilosia pascuorum (Figs 1B, 1C, 2C, 2D); theca of hypandrium in ventral view with large quadrilateral excavation (Figs 4A, 4B).

FEMALE (Figs 6A, 6B, 7, 9B, 10, 11B). Similar to the male, except for normal sexual dimorphism and the following characters: pile is general shorter and more extensively pale, and legs less dark, basal 1/4 of femora, basal 1/3 and apical 1/4 of tibiae pale; frons with two lateral channels, shiny, except dusted antero-lateral corners (Fig. 6 B), covered with pale hairs, except a few black hairs around ocellar triangle and above antennae; thorax pale haired, except for a few black hairs on post-alar calli and near wing base; tibiae of fore and middle legs pale, except dark central ring; basal tarsi of fore and middle legs pale; tergites covered with long and erect hairs, except adpressed hairs on central part of tergites 1-4.

Size. Male, body length: 8.9-11.1 mm; wing length: 7.9-9.2 mm (14 specimens were measured). Female, body length: 10.5 mm; wing length: 8.7 mm (1 specimen was measured).

Diagnosis.

Species related to Cheilosia pascuorum , but differs in the following characteristics: face covered with long hairs (Figs 5, 6), bare in Cheilosia pascuorum ; clypeus dusted, shining in Cheilosia pascuorum ; male genitalia: dorsal lobe of gonostylus without distinct dorsolateral extension (Figs 1A, 2A, 2B), present in Cheilosia pascuorum (Figs 1B, 1C, 2C, 2D).

Based on the identification keys for European hoverflies, this species can be confused with four other Cheilosia species which have long facial hairs: Cheilosia barbata (Fig. 3A), Cheilosia lasiopa Kowarz, 1885 (Fig. 4D), Cheilosia melanopa (Fig. 4E) and Cheilosia vulpina (Fig. 4C). Identification of the new described species is possible based on a combination of the following characters: arista bare; central disc of scutum shining; vein M1 meeting vein R4+5 at an obtuse angle (Fig. 7: x); tergites 1-3 pale haired; sternites obviously grey dusted; male: dorsal lobe of gonostylus broader basally (Fig. 8A); female: arista about 3 times as long as third antennal segment (Fig. 11B); hairs on scutum long and erected (Fig. 9B); hind tibia on posterodorsal surface with few longer hairs (Fig. 10: y).

Etymology.

The specific epithet is derived from the Latin nouns (in apposition) of feminine gender in the nominative case: “barba” (beard) and “facies” (face). The name indicates the presence of long hairs on the face.

Distribution

(Fig. 13). Cheilosia barbafacies sp. n. is found in two Dinaric mountains in the central part of the Balkan Peninsula, in Durmitor (Montenegro) and Jahorina (Bosnia-Herzegovina), while the related species, Cheilosia pascuorum , has a wider range extending from the Alps, across the Balkan Peninsula, to Romania and the European part of Russia ( Speight 2012). Both species appear sympatrically within one refuge area rich in endemics and relict species (Durmitor mountain, gorge of river Sušica and glacial lakes Škrčka jezera) ( Šimić 1987, Vujić 1996).

Discussion.

Although Cheilosia barbafacies has long facial hairs, it is closely related to Cheilosia pascuorum with a non-hairy face. Species with long facial hairs were assigned to "group B " of Sack (1928-1932), based on Becker’s (1894) revision of the genus. Also recent authors (e.g. Bartsch et al. 2009) still use this old name ("group B") in their keys for practical reasons. In his recent classification of the genus, Barkalov (2002) included taxa with long facial hairs in seven out of his thirteen subgenera, i.e. subgenera Cheiloisa s.str., Convocheila Barkalov, 2002, Endoiasimyia Bigot, 1882, Floccocheila Barkalov, 2002, Hiatomyia Shannon, 1922, Neocheilosia Barkalov, 1983 and Taeniochilosia Oldenberg, 1916. Phylogenetic analysis of the relationship between the genus Cheilosia and the tribe Rhingiini , based on mtDNA COI gene sequence ( Ståhls et al. 2004), revealed that Cheilosia species with this character state can be found in eight clades (see Fig. 1 in Ståhls et al. 2004). It seems clear that the length of the facial pilosity is not a synapomorphic character of any species group, and might evolve several times within the genus Cheilosia .

In Bartsch et al. (2009), specimens of Cheilosia barbafacies key out to Cheilosia vulpina (group B), and in Van Veen (2004), males and females with dark-brown antennae can be identified as Cheilosia vulpina , while specimens with reddish antennae are Cheilosia barbata . For the separation of Cheilosia barbafacies from Cheilosia barbata , diagnostic characters of the proxima group can be used, and the distinction between Cheilosia vulpina and Cheilosia barbafacies sp. n. is presented in the following key.

Some females of Cheilosia barbafacies sp. n. are similar to females of Cheilosia redi , and they can be separated by the following characters:

Cheilosia barbafacies sp. n.: vein M1 meeting vein R4+5 with an obtuse angle (Fig. 7: x); hairs on scutum and tergites long and erected (Fig. 9B); hind tibia on posterodorsal surface with few longer hairs (Fig. 10: y).

Cheilosia redi : vein M1 meeting vein R4+5 with an acute angle; hairs on scutum and tergites shorter and significantly adpressed; hind tibia on posterodorsal surface without long hairs.