Cheilosia nigella, Barkalov & Ståhls, 2022

Barkalov, Anatolij V. & Ståhls, Gunilla, 2022, Cheilosia (Diptera, Syrphidae: Rhingiini) of Nepal with descriptions of 29 new species, European Journal of Taxonomy 829 (1), pp. 1-127 : 81-84

Cheilosia nigella sp. nov.

urn:lsid:zoobank.org:act:EFF151DD-587E-41AC-BB8C-4846BBD45812

Figs 45 , 46A–B

Differential diagnosis

Cheilosia (Montanocheila) nigella sp. nov. shares the characters like dense, long pilosity of body, big size, broad body and structure of male genitalia with the other members of the subgenus. Among the Nepalese taxa C. (M.) nigella sp. nov. is most similar to C. (M.) brevimontana sp. nov., but differs by having mostly yellow pilosity of scutellum (vs black in C. brevimontana sp. nov.), mostly orange pilosity of abdomen (vs mainly yellowish in C. brevimontana sp. nov.) and brownish basal parts of tibiae (vs black in C. brevimontana sp. nov.).

Etymology

The specific epithet is from the Latin ‘ nigellus ’and is the diminutive form of ‘ niger ’, meaning ‘blackish’.

Material examined

Holotype NEPAL • ♂; Distr. Humla, 14 km W of Simikot 3 km NW of Sankha La; 29°57′18″ N, 81°39′30″ E; 4300 m a.s.l.; 29–30 Jun. 2001; F. Creutzburg leg.; “[Kante Tragant]”; NME.

Description

Male

LENGTH. Body 13.5 mm, wing 12.5 mm.

HEAD. Face rather broad, convex, in anterior view ventrally slightly broadened, black, almost completely covered with dense grey pollinosity except tip of facial tubercle and lower part near mouth margin only slightly pollinose or bare, pollinosity dense in dorsal part of face; non-pilose (but with some distinct microtrichia latero-medially); facial tubercle small, not prominent; parafacia relatively broad, clearly broader than ½ width of basoflagellomere, grey pollinose along eye and shiny towards face, long yellow pilose in dorsal ⅕ and otherwise with very long black pilosity. Gena broad, densely grey pollinose and comparatively short black pilose. Frons broad and convex, finely grey pollinose and long black pilose; frontal angle obtuse; lunule black; antennal pits broadly separated. Antenna black; basoflagellomere grey pollinose, rounded, ventral margin obscurely brownish-red; arista narrow, long, black, bare. Eye completely densely black pilose; eye contiguity about equal to length of frons without lunule; narrow orange spot ventral to eye. Vertex black, grey pollinose and long, black pilose; ocellar triangle isosceles. Occiput laterally black pilose, medially yellow pilose.

THORAX. Postpronotum black, black pilose. Scutum black, very finely punctured, black pilose; slightly pollinose; with four longitudinal vittae of grey pollinosity, lateral vittae extend from anterior part of scutum almost to postalar calli, medial vittae extend from anterior margin to ⅔ of scutum; mainly long yellow pilose, mixed with scattered black pilosity, mainly black pilose on lateral parts; postalar calli long yellow pilose; scutellum long yellow pilose and with some fine black shorter pile medially; scutellum margin lacking black bristles, length of yellow pilosity up to length of scutellum. Subscutellar fringe long, dense, yellow. Pleura slightly shiny but grey pollinose, with long black pilosity; anterior anepisternum non-pilose, posterior anepisternum without strong bristles; katepisternum completely black pilose. Metasternum black pilose.

LEGS. Coxa black; fore coxa grey pollinose, fore coxa without baso-lateral spur; femora black with narrowly yellow tips, long, black pilose; tibia brownish on basal ½–⅓ and narrowly on tips, black in other parts; tarsi dorsally black.

WING. Completely covered with microtrichia, slight brownish, veins yellow in basal ⅓ and black in apical ⅔; vein Rs with a few black pile; M 1 meeting R 4+ 5 in an obtuse angle. Calypter pale-brown with yellow fringe; haltere dark-brown to black.

ABDOMEN. Comparatively narrow, narrower than mesonotum at level of wing base, black, finely punctured, grey pollinose, with dense, long, erect pilosity; tergites I–II with black pilosity medially, laterally with yellow pilosity, posterior parts of tergite II with some orange pile; tergites III–IV foxy-orange pilose; all tergites also with long black pilosity along lateral margins. Sternites grey pollinose, long black pilose, sternites III and IV with short, adpressed black pilosity postero-medially. Pre-genital segments black pilose. Gonopod of male genitalia lacks the left process and with a long, bent right process.

Female

Unknown.

Distribution

Nepal.

Figures

Fig. 45. Cheilosia (Montanocheila) nigella sp. nov., holotype, ♂ (NME). A. Head, lateral view. B. Same, dorsal view. C. Tip of wing. D. Antenna, lateral view of pedicel and basoflagellomere. E. Surstylus and gonocercus, lateral view. F. Superior lobe of hypandrium, lateral view. G. Aedeagus and aedeagal apodeme, lateral view. Scale bars indicated in drawings.

Fig. 46. A–B. Cheilosia (Montanocheila) nigella sp. nov., holotype, ♂ (NME); dorsal and lateral views. – C–D. Cheilosia (Montanocheila) pernigra sp. nov., holotype ♀ (ZSMC); dorsal and lateral views. Photo: Pekka Malinen, FMNH Luomus. Scale bars = 1 mm.