Cheilosia insolita, 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 : 64-66

Cheilosia insolita sp. nov.

urn:lsid:zoobank.org:act:7DE2FE7F-5F7E-44C7-87D9-1C56D24083FA

Figs 32D–E , 34

Differential diagnosis

The presence of for the genus Cheilosia unusual characters such as pale yellowish-brownish body colour, the colour pattern of frons ( Fig. 34B ), and a whitish stigma of wing, distinguishes C. insolita sp. nov. from all other congeners. The taxon is here placed as incertae sedis within the genus Cheilosia (meaning that the subgeneric placement is unclear) while no male specimen is available for study, and the structures of male genitalia provides critical characteristics for establishing a subgeneric rank of this species.

Etymology

The specific epithet is from the Latin ‘ insolitus ’, meaning ‘unusual, rare’, referring to the unusual colour of the species.

Material examined

Holotype NEPAL • ♀; Gosainkunde ; 19 800 ft a.s.l.; 27 Jun. 1967; Can. Nepal Exped.; CNC.

Description

Female

LENGTH. Body 8.0 mm; wing 7.3 mm.

HEAD. Face broad, in anterior view distinctly broadened ventrally, in lateral view protruded forward; pale-brown; finely grey pollinose except shiny on facial tubercle and along mouth margin, and in dorsal part near parafacia; facial tubercle moderate in size; parafacia very broad, in broadest part approximately equal to width of basoflagellomere, dark-brown, densely grey pollinose, with long, dense whitish pilosity mixed with some shorter dark-brown, semi-erect pilosity. Gena broad, pale-brown, densely grey pollinose and comparatively long white pilose; ventral part of occiput along eye densely grey pollinose, with dense white pilosity. Frons broad, distinctly broadened anteriorly, yellow in anterior and medial part and black within lateral furrows; with dense, erect and semi-erect, comparatively long, black pilosity mixed with shorter yellowish pilosity (some long black pile inclined towards either eye). Lunule bright yellow, antennal pits distinctly separated. Antenna all black; basoflagellomere rounded, densely grey pollinose and with a small brownish spot in postero-ventrally; arista short, black, shiny, bare. Vertex flat, shiny, long black pilose. Dorsal part of occiput pale-brown, shiny, with long black and short yellow pilosity.

THORAX. Postpronotum yellow, with yellow pilosity. Scutum pale-brown, shiny, covered with comparatively short black pilosity, erect in anterior half and semi-erect in posterior half. Postalar callus yellow, with short, bristle-like, black pilosity. Scutellum yellowish, with short yellow and some black pilosity; scutellum hind margin with short yellow pilosity and with two black fine bristles. Subscutellar fringe short, yellow. Pleura pale brown, finely grey pollinose, without shiny spots, with erect white pilosity, postero-dorsal corner of posterior anepisternum with black pilosity. Metasternum with long white pilosity.

LEGS. Fore trochanter dark-brown, without baso-lateral spur; mid trochanter dark-brown anteriorly and pale-brown dorsally and posteriorly; hind trochanter pale-brown. Fore and mid femora anteriorly basally narrowly black, and with broader black annulus apically, with yellow tip; posteriorly entirely yellowishbrown; hind femur yellowish-brown, antero-basally with small black spot and with incomplete annulus in apical third; long pilosity on posterior part of fore and mid femora mostly white with some black pilosity at base and tip; ventral part of hind femur with short black and yellow pilosity. Tibiae yellow in basal ⅓–½ and on tips, otherwise brown. Fore and hind tarsi black dorsally, 1–3 segments of mid tarsus yellow, 4–5 segments black; all tarsi yellow ventrally.

WING. Comparatively broad, light with white stigma and all veins pale-yellow in basal half; entirely microtrichose; inner angle between venae M 1 and R 4+5 right. Calypter white with yellow rim and pilosity; haltere yellow.

ABDOMEN. Comparatively narrow, in broadest part almost equal to width of mesonotum at level of wing base; shiny, pale-brown, with dark spots on postero-medial part of tergites II–III; laterally with short erect pilosity and with semi-erect white pilosity on other parts. Sternites pale-brown, with short white pilosity.

Male

Unknown.

Distribution

Nepal.

Figures

Fig. 32. A. Cheilosia (Endoiasimyia) indiana (Bigot, 1883), female head (CNC). – B–C. Cheilosia (Floccocheila) indistincta sp. nov., holotype, ♂ (IBSJW/NME); dorsal and lateral views. – D–E. Cheilosia insolita sp. nov., holotype, ♀ (CNC); dorsal and lateral views. Photo: Pekka Malinen, FMNH Luomus. Scale bars = 1 mm.

Fig. 34. Cheilosia insolita sp. nov., holotype, ♀ (CNC). A. Head, anterior view. B. Head, dorsal view. C. Mid leg, anterior view. D. Tip of wing. E. Antenna, lateral view of pedicel and basoflagellomere. Scale bars indicated in drawings.