Cheilosia ( Taeniochilosia ) ouwehandae Bot, 2025

Bot, Sander, Mengual, Ximo, Meutter, Frank Van de & Skevington, Jeffrey H., 2025, Review of the genus Cheilosia Meigen, 1822 (Diptera: Syrphidae) from the Caucasus, with the description of 14 new species, European Journal of Taxonomy 1023, pp. 1-181 : 102-104

Cheilosia ( Taeniochilosia) ouwehandae Bot sp. nov.

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Fig. 51

Differential diagnosis

Cheilosia ouwehandae sp. nov. is only known from the male holotype, thus the differential diagnosis applies to males only. Cheilosia ouwehandae belongs to the subgenus Taeniochilosia by the combination of bare eye, black legs and the anterior process of lunula not broadly confluent with the face ( Barkalov & Ståhls 1997). Genetically similar to C. aenigmatosa , it differs morphologically as follows: smaller (body size 6.5 mm vs 8–9.5 mm), face and parafacia slightly pruinose (more densely pruinose in C. aenigmatosa ), facial tubercle better developed, projecting well beyond mouth edge ( Fig. 51B) (less developed, less protruding, not beyond mouth edge in C. aenigmatosa ; Fig. 2C), postpedicel basoventrally orange (black in C. aenigmatosa ), frontal triangle with black pile (with large proportion of pile yellow in C. aenigmatosa ), pile on scutum whitish instead of golden, posterior margin of scutellum with black setae instead of black pile and abdomen with more dense pruinosity. Cheilosia ouwehandae can be confused with extralimital C. sahlbergi and C. vangaveri Timon-David, 1937 . It differs from C. sahlbergi and C. vangaveri by dense pruinose frons (slightly pruinose or shiny in C. sahlbergi , shiny in C. vangaveri ), pruinose parafacia (shiny in C. sahlbergi and C. vangaveri ), abdomen with completely yellow pile (partly with black pile in C. sahlbergi ), terga II–IV completely pruinose (lateral margins shiny in C. sahlbergi and C. vangaveri ) and sterna III–IV with mainly adpressed yellow pile (laterally with erect pile in C. sahlbergi and C. vangaveri ).

Etymology

This species is named after Janne Ouwehand, the beloved wife of the author of the species, who together with her husband collected the holotype. Species epithet to be treated as a noun in the genitive case.

Material examined

Holotype

GEORGIA • ♂; Samegrelo-Zemo Svaneti, Ushguli ; 42.911° N, 42.938° E; 2480 m a.s.l.; 27 Jun. 2018; S. Bot leg.; ZFMK, SB.003219 = CNC databasing S. Bot 755.

Description

Male

LENGTH. Body 6.5 mm, wing 5.5 mm.

HEAD. Face bare, with facial tubercle, black, slightly pruinose, more densely pruinose below lunule. Mala pruinose. Parafacia black, wide, about as wide as postpedicel, pruinose, white pilose. Length of eye contiguity slightly shorter than the length of frons. Angle of approximation of eyes 95°. Frontal triangle black, pruinose, long black pilose, with narrow yellow pile anteriorly, with medial frontal sulcus. Ocellar triangle shiny, long black pilose. Occiput pruinose, with short yellow and long black pile. Lunule black, medial arm on lunule absent, antennal fossa present. Scape and pedicel black with black setae; postpedicel rounded, about as wide as high, basoventrally orange, otherwise black. Arista black, basal quarter thickened, short pilose, longest pilosity half as long as width of arista at base. Eye bare.

THORAX. Scutum black, shiny except narrowly anteriorly and notopleuron slightly pruinose, finely punctured, with short erect whitish and sparser long erect black pile. Scutellum black, shiny, anteriorly narrowly pruinose, with short whitish pile and sparse black pile, posterior margin with black setae, length of setae just shorter than length of scutellum. Pleura black, pruinose, with yellow pile, except posterior anepisternum with mixed yellow and black pile, dorsal and ventral pile patches on katepisternum widely separated. Haltere with pedicellum yellow, capitulum dark brown to black.

WING. Wing including alula entirely microtrichose; veins black; stigma brown.

LEGS. Coxae and trochanters black. Femora, tibiae and tarsi black, pruinose. Profemur and mesofemur ventrally and anterolaterally with long mixed yellow and black pile; metafemur ventrally with short yellow pile and some black setae. Tibia with short adpressed yellow and black pile. Tarsi dorsally with black pile, ventrally yellow and black pilose.

ABDOMEN. Terga I–IV laterally with long erect yellow pile, in center with short adpressed yellow pile; tergum I pruinose, terga II–III pruinose, in center pruinosity less dense, tergum IV pruinose, most dense pruinosity on anterior part. Sterna I–II with erect yellow pile, sterna III–IV with short adpressed yellow pile, sterna I–IV thickly pruinose. Genitalia with surstylus about twice as long as wide. Dorsal and ventral lobes of postgonite pointed.

Female

Unknown.

Genetics

See Remarks under C. aenigmatosa . The DNA barcode of the holotype is placed between two well-supported clusters of C. aenigmatosa .

Biology

The holotype was collected just above the tree line in an area with a mixture of extensive grasslands and Rhododendron ( Rhododendron sp. ) at 2480 m a.s.l.

Distribution

Only known from the type locality from the Greater Caucasus in Georgia.