Cheilosia ( Montanocheila ) contrasta, Bot & Mengual & Meutter & Skevington, 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 : 49-53

Cheilosia ( Montanocheila) contrasta sp. nov.

urn:lsid:zoobank.org:act:

Figs 23–24

Differential diagnosis

Cheilosia contrasta sp. nov. belongs to the subgenus Montanocheila . From all Montanocheila known from the Palaearctic Region (see Claussen 1998), the male differs by the following combination of characters: postpedicel predominantly orange ( Fig. 24A), tibiae yellow at both ends ( Fig. 23A), terga I–II with yellow pile contrasting with black pile on terga III–IV ( Fig. 23A–B) and surstylus more than twice as long as wide, with pointed apex ( Fig. 24D). In the male genitalia, the shape of the surstylus is very characteristic and only C. pictipennis Egger, 1860 has a similar looking surstylus; however, in C. contrasta sp. nov. the apex of the surstylus is more pointed (rounded in C. pictipennis ). Moreover, both sexes can be distinguished from C. pictipennis by the uninterrupted long pilosity on anterior part of sternum II (in C. pictipennis the anterior part of sternum II is bare or short pilose medially) and by the characteristic bicoloured pilosity on abdomen, which is more variable in C. pictipennis . The female is very similar to that of C. subpictipennis , yet, the pile on terga III–V are long and black, while the pilosity on terga III–V is shorter and yellow in C. subpictipennis .

Etymology

The species name ‘ contrasta ’ refers to a characteristic feature of the species: the predominantly yellow pile on terga I–II contrasting sharply with the predominantly black pile on terga III–IV. Species epithet to be treated as an adjective.

Material examined

Holotype

GEORGIA • ♂; Imereti, road from Abastumani to Sairme ; 41.8380° N, 42.8183° E; 2260 m a.s.l.; 10 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-TIS-8006786 = ZFMK-DIP-00066187 .

Paratypes

ARMENIA – Ararat Province • 1 ♀; surroundings Geghard Monastery ; 40.1385° N, 44.8172° E; 1720 m a.s.l.; 22 May 2022; X. Mengual leg.; ZFMK, ZFMK-DIP-00093557 = ZFMK-TIS-8014524 ; ZFMK . – Syunik Province • 1 ♂; from Lichk to the Zvaravank Monastery ; 39.0549° N, 46.1713° E; 1765 m a.s.l.; 16 May 2022; X. Mengual leg.; ZFMK, ZFMK-DIP-00093035 = ZFMK-TIS-8014426 .

GEORGIA – Adjara • 1 ♂; Kintrishi Nature Reserve ; 41.75517° N, 42.11249° E; 2268 m a.s.l.; 2–16 Jun. 2018; GGBC-members leg.; Malaise trap, stored in alcohol; ZFMK, ZFMK-TIS-8010561 . – Kakheti – 1 ♀; Lagodekhi N.P. ; 41.8767° N, 46.2429° E; 615 m a.s.l.; 2 May 2023; S. Bot leg.; SBA, SB.003118 • 1 ♀; Lagodekhi N.P. ; 41.8777° N, 46.2436° E; 625 m a.s.l.; 2 May 2023; F. Van de Meutter leg.; FMT . – Mtskheta-Mtianeti • 1 ♂; Lutkhubi ; 42.3797° N, 44.7969° E; 1463 m a.s.l.; 6 May 2023; S. Bot leg.; SBA, SB.003117 • 4 ♂♂; Lutkhubi ; 42.3936° N, 44.7923° E; 1760 m a.s.l.; 8 May 2023; F. Van de Meutter leg.; FMT . – Samegrelo-Zemo Svaneti • 1 ♂; Ushguli ; 42.950° N, 43.075° E; 2275 m a.s.l.; 24 Jun. 2018; S. Bot leg.; SBA, SB.003119 = CNC databasing S. Bot 649 • 2 ♂♂; Mestia ; 43.1178° N, 42.7251° E; 1875 m a.s.l.; 14 Jun. 2019; F. Van de Meutter leg.; FMT • 1 ♂; near Ushguli ; 42.9498° N, 43.0718° E; 2270 m a.s.l.; 15 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-DIP-00066188 = ZFMK-TIS-8006787 • 1 ♀; Ushguli ; 42.90° N, 42.93° E; 2600 m a.s.l.; 17 Jun. 2019; J. van Steenis leg.; JSB, 2019-00.888 • 1 ♀; Ushguli ; 42.898° N, 42.008° E; 2601 m a.s.l.; 18 Jun. 2019; S. Bot leg.; SBA, SB.003120 = CNC databasing S Bot 917 . – Samtskhe-Javakheti • 1 ♀; Dviri ; 41.7543° N, 43.2733° E; 1100 m a.s.l.; 12 May 2023; W. Opdekamp leg.; WOR, B028 .

Description

Male

LENGTH. Body 12–13.5 mm, wing 11.5–12 mm.

HEAD. Face slightly protruding downwards, bare, with facial tubercle, black, shiny except grey pruinose narrow strip along parafacia, on genae and a broad weakly delimited band directly below lunule. Parafacia black, broad, almost as wide as postpedicel, slightly pruinose, long white pilose. Frontal triangle black, shiny, except narrowly pruinose along eye margins and along face, long white pilose, with medial frontal sulcus. Length of eye contiguity about as long or slightly shorter than the length of frons. Angle of approximation of eyes 80–90°. Vertical triangle black, pruinose; ocellar triangle shiny and long yellow pilose. Occiput pruinose, yellow pilose. Lunule dark orange, with distinct medial arm, separating acetabula. Scape blackish, anteriorly with setae, inner setae yellow, outer setae black; pedicel blackish, becoming orange on outer third, anteriorly with black setae and yellow pile; postpedicel orange, sometimes darkened in dorsal outer corner, about as high as wide, rounded, pruinose; arista black, sometimes orange apically, almost bare. Eye long white pilose.

THORAX. Scutum black, finely punctured, with long erect yellow or orange pile, shiny except anteriorly narrowly pruinose and notopleuron slightly pruinose. Scutellum black, shiny, with long and short erect golden yellow pile, posterior margin without setae. Pleura black, pruinose, with yellow white pile; katepisternum continuously pilose. Haltere pedicellum yellow, capitulum dark brown or black.

WING. Wing including alula entirely microtrichose, veins on outer two third of wing darkened dark brown (most so at veins m-cu, M 4 base, r-m, R 2+3, R 4+5 and M 2), inner angle between veins M 1 and R 4+5 equal to 90°, wing veins orange in the basal part and black in the apical part of the wing.

LEGS. Coxae black, with yellow pile. Trochanters black. Femora black, very apex orange; profemur and mesofemur with yellow pile except ventrally on apical half with black pile; metafemur with yellow anterolateral pile, pile longer than width of metafemur, ventrally with scattered long yellow pile and short semi-adpressed mixed yellow and black setae, towards apex setae exclusively black. Tibiae yellow with vague black ring or smudge below middle; tibiae with yellow pile, sometimes mixed with black pile. Tarsi with mixed yellow and black pile; black, except ventrally orange on basal four tarsomeres and sometimes basal two tarsomeres of mesotibia dark orange dorsally.

ABDOMEN. Pile on terga I–IV long and erect, terga I–II with mainly yellow pile, terga III–IV with mainly black pile, tergum II in posterolateral corner with variable small black pile and posteriorly in center with mixed black and yellow pile; tergum IV sometimes with a narrow band of yellow pile on anterior margin. Tergum I pruinose, tergum II pruinose in center and anteriorly, terga III–IV shiny. Sterna I–II with long erect golden pile, sterna III–IV with long erect black pile, shorter and adpressed in central part; sternum I pruinose; sternum II shiny but pruinose anteriorly and laterally, sternum III shiny and sternum IV shiny but pruinose posteriorly. Genitalia with surstylus about 2,9 times as long as wide ( Fig. 24D); ventral lobe of postgonite more than twice as long as dorsal lobe of postgonite ( Fig. 24C); sclerite of the distiphallus with two ventral spurs.

Female

LENGTH. Body 11.5–13.5 mm, wing 11 mm.

Similar to the male, except for normal sexual dimorphism and the following characters. Face more extensively pruinose. Frons shiny, except a narrow strip along eye margin in anterior part. Lunule yellow. Scape, pedicel and postpedicel bright orange. Postpedicel larger than in the male. Capitulum of haltere orange. Pile on the central part of tergum II adpressed. Tergum V shiny, with long erect black pile. Sternum V with long erect black pile, shiny with pruinose posterior margin.

Genetics

All DNA barcodes of C. contrasta sp. nov. group together without high support (BS <90%).

Distribution

So far only known from the type locations in the Greater and Lesser Caucasus in Armenia and Georgia.

Biology

Collected on forest clearings and on alpine meadows in mountains between 615 and 2601 m a.s.l. Males have been seen hovering in small groups at 1.5 m in the shelter of the last trees near a glacier, in forest clearings near the treeline, at the treeline and 0.5 m above the ground in wind-sheltered hollows along a small mountain stream. Males and females visit flowers of Salix sp. Females have been observed to crawl on and underneath Heracleum sp. leaf rozettes which may indicate that they oviposit here, and that larvae are associated with this plant.