Cheilosia ( Cheilosia ) megaclama, 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 : 88-92

Cheilosia ( Cheilosia) megaclama sp. nov.

urn:lsid:zoobank.org:act:

Figs 44–45

Differential diagnosis

Cheilosia megaclama sp. nov. belongs to the subgenus Cheilosia . In the Caucasus, the male can be confused with those of C. aurantia sp. nov. and C. albipila . It is best distinguished from that of C. aurantia by the yellow pile on the eye ( Fig. 44B) (longer and black in C. aurantia Fig. 9A) and it can be separated from that of C. albipila by the wider face, below the antenna about as wide as an eye ( Fig. 44D) (about half as wide as an eye in C. albipila ) and the katepisternal hair patches that are separated or only narrowly connected by short pile (katepisternal hair patches connected broadly by long pile in C. albipila ). Because the eyes are bare in the female, contrary to the male, the female of C. megaclama can be confused with those of C. uviformis and C. atypica , but it differs from the former by the truly bare eye (some short scattered pile on eye in C. uviformis ) and wider parafacia ( Fig. 45D), and it can be distinguished from the latter by the darker legs: tibiae with black ring and tarsi mainly black (tibiae with indistinct ring and tarsi dorsally mostly yellow, except first, fourth and fifth segments of protarsus and fifth segment of mesotarsus black in C. atypica ). Cheilosia megaclama is especially similar to the extralimital C. clama Claussen & Vujić, 1995 occurring in Central Europe. The male of C. megaclama differs from that of C. clama by a larger body size (average 10.5 mm instead of maximum 8.8 mm in C. clama ), slightly narrower face, shiny parafacia (parafacia pruinose in C. clama ), longer eye contiguity (0.8 times the length of frons in C. megaclama vs 0.5 to 0.55 in C. clama ), angle of approximation of eyes smaller (90° vs 100–110° in C. clama ), wing veins blackish in basal half in C. megaclama instead of yellow in C. clama , metafemur ventrally with predominantly orange instead of black setae in C. clama , and differences in the male genitalia: postgonite with ventral lobe shorter and dorsal lobe longer. The female of C. megaclama differs from that of C. clama by larger size (on average over 9 mm vs around 7 mm), the longer body pile (pile much longer on, e.g., scutum, pleura and abdomen in C. megaclama ) and by wing veins blackish in basal half in C. megaclama instead of yellow in C. clama .

Etymology

The species name derives from the Greek prefix ‘ mega -’ meaning ‘large’ ( Brown 1956: 517) applied to the name clama to mean ‘large clama ’ and it refers to the general similar appearance of our new species to C. clama and the difference in size. Species epithet to be treated as a noun in apposition.

Material examined

Holotype

GEORGIA • ♂; Mtskheta-Mtianeti, Lutkhubi ; 42.3984° N, 44.7996° E; 2068 m a.s.l.; 8 May 2023; S. Bot leg.; ZFMK, SB.003216 = ZFMK-TIS-8027979.

Paratypes

GEORGIA – Mtskheta-Mtianeti • 1 ♂; Lutkhubi ; 42.3984° N, 44.7996° E; 2068 m a.s.l.; 8 May 2023; S. Bot leg.; SBA, SB.003217 • 1 ♀; same data as for preceding; SBA, SB.003218 = ZFMK-TIS-8027980 • 1 ♂; Lutkhubi ; 42.3936° N, 44.7923° E; 1760 m a.s.l.; 8 May 2023; F. Van de Meutter leg.; FMT • 1 ♀; same data as for preceding; ZFMK • 1 ♂; Lutkhubi ; 42.3989° N, 44.7995° E; 2100 m a.s.l.; 8 May 2023; W. Opdekamp leg.; ZFMK, D004 . – Samegrelo-Zemo Svaneti • 1 ♀; Ushguli, close to river Inguri ; 42.9500° N, 43.0719° E; 2270 m a.s.l.; 15 Jun. 2019; F. Van de Meutter leg.; FMT, ZFMKTIS-8012674 . – Samtskhe-Javakheti • 1 ♂; Kodiani ; 41.7268° N, 43.3490° E; 2150 m a.s.l.; 10 May 2023; W. Opdekamp leg.; WOR, B002 .

Description

Male

LENGTH. Body 10.5–11 mm, wing 8–8.5 mm.

HEAD. Face black, bare, with facial tubercle, thick pruinose below lunule, slightly pruinose, except facial tubercle and mouth edge shiny and with dense pruinose band below lunule, below lunule slightly less wide than an eye. Parafacia black, shiny or slightly pruinose, white pilose, about 0.8 times as wide as postpedicel. Clypeus shiny, about 1.5 to 1.9 times as long as wide measured from the midline. Frontal triangle black, pruinose, swollen, with long black and yellow pile, black pile usually dominating, with medial frontal sulcus. Length of eye contiguity about 0.8 times the length of frons. Angle of approximation of eyes 90°. Vertical triangle black, ocellar triangle long black and yellow pilose. Occiput pruinose, short yellow and long black pilose. Lunule dark orange to blackish, with distinct medial arm, separating acetabula. Scape black; pedicel black or dark orange; postpedicel orange, sometimes dorsal outer corner darkened, 1.25 to 1.5 times as wide as high; arista black, thickened in basal one third, with very short pile, pile much shorter than diameter of arista at base. Eye entirely covered with yellow pile.

THORAX. Scutum black, shiny, finely punctured, with erect yellow-white pile, with a few black pile intermixed near wing base, on postalar callus and in anterolateral corners. Scutellum shiny or slightly pruinose, with long erect yellow-white pile, without setae along posterior margin. Pleura black, slightly pruinose, with yellow pile; metasternum with long whitish pile; dorsal and ventral pile patches on katepisternum narrowly separated but usually connected by shorter pile. Haltere pedicellum orange, capitulum dark brown.

WING. Wing including alula entirely microtrichose, hyaline except in anterior half where slightly dark brown infuscated, wing veins brown in the basal part and black in the apical part of the wing.

LEGS. With black and yellow piles. Coxae, trochanters black. Femora black except apices narrowly yellow, with black and yellow piles; metafemur ventrally with orange semi-adpressed setae, with a few black ones intermixed. Tibiae orange except with black ring below the middle occupying one third of pro- and mesotibia and 40% of metatibia. Protarsus black except basal three tarsomeres ventrally orange; mesotarsus black except basal four tarsomeres ventrally orange and basal two tarsomeres dorsally dark orange to blackish; metatarsus black except basal four tarsomeres ventrally orange.

ABDOMEN. Entirely with yellow-white pile. Terga I–IV medially pruinose and with adpressed short pile, laterally shiny and with long erect pile. Sternum I medially shiny, laterally pruinose, with long erect pile, sternum II slightly pruinose, except with shiny median longitudinal stripe, with long erect pile, sterna III–IV slightly pruinose, medially with short adpressed pile, laterally with long erect pile. Genitalia with surstylus 1.3 to 1.5 times as long as wide, with keel ( Fig. 44F); dorsal lobe of postgonite roughly triangular ( Fig. 44E).

Female

LENGTH. Body 8.5–10 mm, wing 7–8.2 mm.

Similar to the male, except for normal sexual dimorphism and the following characters. Face more extensively shiny, also sides of face shiny. Frons shiny, with erect yellow pile, with wide paravertica. Pile ocellar triangle yellow. Dorsal third of occiput shiny along eye. Eye bare. Scutum with erect dense yellow pile, without black pile intermixed in anterolateral part. Capitulum of haltere yellow to brownish. Metafemur ventrally with orange pile. Terga I–IV completely covered with yellow pile, long and erect along lateral margins, adpressed and shorter medially. Terga II–IV shiny. Sternum IV shiny except posterior margin pruinose.

Genetics

DNA barcodes of C. megaclama sp. nov. are resolved together with high support (BS = 100%).

Biology

All specimens but one collected in early May on flowering Salix sp. at the snow line between 1760– 2150 m a.s.l. One female collected in June at 2270 m a.s.l. in a U-shaped valley on flowering Salix sp.

Distribution

So far only known from the localities of the type series in the Greater and Lesser Caucasus in Georgia.