Cheilosia ( Cheilosia ) caucasi, 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 : 38-43

Cheilosia ( Cheilosia) caucasi sp. nov.

urn:lsid:zoobank.org:act:

Figs 18–19

Differential diagnosis

Cheilosia caucasi sp. nov. most closely resembles C. abagoensis , C. gemmula sp. nov. and C. rhynchops . Both sexes look like C. rhynchops but face not protruding, facial tubercule not low on face (in C. rhynchops the face is protruding, with facial tubercle low on face), postpedicel black ( Fig. 19A–B) (postpedicel usually orange basoventrally in C. rhynchops ), pleura predominantly with black pile (with extensive yellow pile in C. rhynchops ), dorsal and ventral pile patches on katepisternum widely separated (variable in C. rhynchops , but in the Caucasian populations these piles are connected by short pile medially). Male differs further from C. rhynchops in having parafacia wider, frons partly pruinose and not swollen (shiny and swollen in C. rhynchops ), occiput dorsally with mixed black and yellow pile (black in C. rhynchops ), eye with less dense, shorter and paler pile, scutum shiny (pruinose on anterior third in C. rhynchops ), scutum with less extensive white pile ( Fig. 18A) and surstylus with microtrichia on dorsal part ( Fig. 19D) (without microtrichia in C. rhynchops ). See the differential diagnosis of C. gemmula for differences between that species and C. caucasi . The new species C. caucasi is similar to C. abagoensis but thorax with black instead of blue-black shine, eye usually with sparser and partly yellow pile (eye with black and dense pile in C. abagoensis ), scutum finely punctured (scutum coarsely punctured in C. abagoensis ), pleura pruinose (largely shiny in C. abagoensis ), wing hyaline (blackish infuscated in C. abagoensis , Fig. 1C), and sternum I largely or entirely pruinose (sternum I largely or entirely shiny in C. abagoensis ). Males of C. caucasi can have sterna quite pruinose, in that case it may look like C. teberdensis and C. paragigantea , however, the katepisternal pile patches are separated as mentioned above in our new species, but connected in C. teberdensis and C. paragigantea . In some cases, females of C. caucasi have bare eyes resembling females of the subgenus Taeniochilosia , but the anterior process of the lunule is broadly confluent with the face (anterior process missing in Taeniochilosia ).

Etymology

The species name is derived from ‘Caucasus’ and can be translated as ‘the Cheilosia of the Caucasus’. Species epithet to be treated as a noun in the genitive case.

Material examined

Holotype

GEORGIA • ♂; Samtskhe-Javakheti, road from Sairme to Tsikhisjvari, hilltop and surroundings ; 41.7251° N, 43.3605° E; 2519 m a.s.l.; 9 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-TIS-8008778 = ZFMK-DIP-00066397 .

Paratypes

GEORGIA – Imereti • 1 ♂; road from Abastumani to Sairme ; 41.8385° N, 42.8194° E; 2260 m a.s.l.; 10 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-DIP-00066400 = ZFMK-TIS-80087812 • 2 ♀♀; road from Abastumani to Sairme ; 41.8385° N, 42.8194° E; 2260 m a.s.l.; 10 Jun. 2019; F. Van de Meutter leg.; FMT • 4 ♂♂; road from Abastumani to Sairme ; 41.8245° N, 42.8482° E; 2165 m a.s.l.; 10 Jun. 2019; J.H. Skevington leg.; CNC, CNC1386101 , CNC1386104 to CNC1386106 . – Kakheti • 1 ♂; Lagodekhi N.P. ; 41.88273° N, 46.32185° E; 1841 m a.s.l.; 3 May 2014; G. Japoshvili leg.; CNC, CNC1547273 • 2 ♂♂; Batsara Nature Reserve ; 42.286542° N, 45.242212° E; 2065 m a.s.l.; 29 May 2022; X. Mengual leg.; ZFMK, ZFMK-DIP-00094028 = ZFMK-TIS-8014638 , ZFMK-DIP-00094029 = ZFMKTIS-8014639 • 1 ♀; Batsara Nature Reserve ; 42.264937° N, 45.259187° E; 1955 m a.s.l.; 29 May 2022; X. Mengual leg.; ZFMK, ZFMK-DIP-00094021 = ZFMK-TIS-8014637 . – Mtskheta-Mtianeti • 1 ♂; Lutkhubi ; 42.3930° N, 44.7929° E; 1700 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, A012 • 2 ♂♂; Lutkhubi ; 42.3797° N, 44.7969° E; 1463 m a.s.l.; 6 May 2023; S. Bot leg.; SBA, SB.003115 = ZFMKTIS-8027988 , SB.003116 • 2 ♂♂, 4 ♀♀; Sno ; 42.6156° N, 44.6148° E; 1850 m a.s.l.; 7 May 2023; F. Van de Meutter leg.; FMT • 1 ♂; Lutkhubi ; 42.3936° N, 44.7923° E; 1760 m a.s.l.; 8 May 2023; F. Van de Meutter leg.; FMT • 1 ♂; Lutkhubi ; 42.3930° N, 44.7929° E; 1734 m a.s.l.; 8 May 2023; W. Opdekamp leg.; WOR, C006 • 1 ♂; Lutkhubi ; 42.3936° N, 44.7923° E; 1760 m a.s.l.; 8 May 2023; F. Van de Meutter leg.; FMT . – Racha-Lechkhumi and Kvemo Svaneti • 2 ♀♀; 42.909° N, 43.142° E; 1900 m a.s.l.; 29 Jun. 2018; S. Bot leg.; SBA, SB.003087 , SB.003088 • 2 ♀♀; 42.888° N, 43.233° E; 1900 m a.s.l.; 30 Jun. 2018; S. Bot leg.; SBA, SB.003096 , SB.003097 • 1 ♀; 42.820° N, 43.159° E; 1400 m a.s.l.; 2 Jul. 2018; S. Bot leg.; SBA, SB.003105 • 1 ♂; near Shovi ; 42.665° N, 43.656° E; 2203 m a.s.l.; 10 Jul. 2021; S. Bot leg.; SBA, SB.003110 . – Samegrelo-Zemo Svaneti • 2 ♂♂; 42.950° N, 43.075° E; 2275 m a.s.l.; 24 Jun. 2018; S. Bot leg.; SBA, SB.003091 , SB.003092 • 1 ♂; 42.948° N, 43.021° E; 2800 m a.s.l.; 25 Jun. 2018; S. Bot leg.; SBA, SB.003090 • 1 ♀; 42.897° N, 43.008° E; 2630 m a.s.l.; 28 Jun. 2018; S. Bot leg.; SBA, SB.003089 • 1 ♀; Ushguli ; 42.916° N, 43.018° E; 2140 m a.s.l.; 29 Jun. 2018; S. Bot leg.; SBA, SB.003086 • 1 ♂; Mestia ; 43.028° N, 42.910° E; 2834 m a.s.l.; 13 Jun. 2019; S. Bot leg.; SBA, SB.003106 • 1 ♀; same data as for preceding; SBA, SB.003107 • 2 ♂♂; 43.0254° N, 42.8906° E; 2550 m a.s.l.; 13 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-DIP-00066402 = ZFMK-TIS-8008783 , ZFMK-DIP-00066403 • 3 ♂♂, 2 ♀♀; 43.0254° N, 42.8906° E; 2550 m a.s.l.; 13 Jun. 2019; F. Van de Meutter leg.; FMT • 1 ♀; 43.0265° N, 42.9100° E; 2860 m a.s.l.; 13 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-DIP-00066404 = ZFMK-TIS-8008784 • 1 ♀; 43.0259° N, 42.9103° E; 2871 m a.s.l.; 13 Jun. 2019; J.H. Skevington leg.; CNC, CNC1386375 • 3 ♂♂; Mestia ; 43.02° N, 42.89° E; 2600 m a.s.l.; 13 Jun. 2019; J. van Steenis leg.; JSB, 2019-00.959 , 2019-01.087 , 2019-01.088 = ZFMK-TIS-8009607 • 1 ♀; 42.948° N, 43.070° E; 2258 m a.s.l.; 15 Jun. 2019; S. Bot leg.; SBA, SB.003108 • 1 ♂; 42.9471° N, 43.0671° E; 2257 m a.s.l.; 15 Jun. 2019; J.H. Skevington leg.; CNC, CNC1386526 • 1 ♀; same data as for preceding; CNC, CNC1386527 • 1 ♂, 1 ♀; 42.9062° N, 42.9370° E; 2615 m a.s.l.; 16 Jun. 2019; F. Van de Meutter leg.; FMT • 1 ♀; 42.900° N, 42.934° E; 2700 m a.s.l.; 17 Jun. 2019; S. Bot leg.; SBA, SB.003109 = CNC databasing S. Bot 922 = CNCTW077-21 = JSM13473 • 2 ♂♂; 2 km SW of Ushguli ; 43.0052° N, 42,8986° E, 2550 m a.s.l.; 17 Jun. 2019; F. Van de Meutter leg.; FMT • 1 ♂; 42.9140° N, 43.0911° E; 2575 m a.s.l.; 18 Jun. 2019; X. Mengual leg.; ZFMK, ZFMK-DIP-00066401 = ZFMKTIS-8008782 • 1 ♂; Zagarari Pass ; 42.91° N, 43.09° E; 2585 m a.s.l.; 18 Jun. 2019; J. van Steenis leg.; JSB, 2019-01.146 • 1 ♀; 42.9125° N, 43.0549° E; 2299 m a.s.l.; 11 Jul. 2021; S. Bot leg.; SBA, SB.003111 • 2 ♀♀; 42.9616° N, 43.0914° E; 2447 m a.s.l.; 12 Jul. 2021; S. Bot leg.; SBA, SB.003112 , SB.003113 . – Samtskhe-Javakheti • 1 ♂; Borjomi N.P.; 41.867° N, 43.251° E; 2000 m a.s.l.; 18 Jun. 2018; S. Bot leg.; SBA, SB003094 = CNC databasing S. Bot 921 = CNCTW076-21 = JSM13472 • 1 ♀; same data as for preceding; SBA, SB.003095 • 4 ♂♂; road from Sakire to Tsikhisjvari ; 41.728° N, 43.364° E; 2327 m a.s.l.; 9 Jun. 2019; S. Bot leg.; SBA, SB.003098 = CNC databasing S. Bot 920, SB.003099 to SB.003101 • 3 ♀♀; same data as for preceding; SBA, SB.003102 to SB.003104 • 2 ♂♂, 5 ♀♀; road from Sakire to Tsikhisjvari ; 41.7251° N, 43.3605° E; 2519m a.s.l.; 9 Jun. 2019; F. Van de Meutter leg.; FMT • 1 ♀; same data as for preceding; X. Mengual leg.; ZFMK, ZFMK-DIP-00066398 = ZFMK-TIS-8008779 • 1 ♀; Borjomi N.P. ; 41.7280° N, 43.3640° E; 2327 m a.s.l.; 9 Jun. 2019; L. Hofstee leg.; LHH • 1 ♂; road from Sakire to Tsikhisjvari ; 41.7299° N, 43.3684° E; 2245 m a.s.l.; 9 Jun. 2019; J.H. Skevington leg.; CNC, CNC1386030 • 1 ♂; Borjomi ; 41.72° N, 43.36° E; 2250 m a.s.l.; 9 Jun. 2019; J. van Steenis leg.; JSB 2019-01.022 , ZFMK-TIS-8009606 • 1 ♀; same data as for preceding; JSB, 2019-01.073 • 1 ♂; Abastumani ; 41.83° N, 42.81° E; 2260 m a.s.l.; 10 Jun. 2019; J. van Steenis leg.; JSB, 2019-01.075 • 1 ♀; Borjomi N.P. ; 41.823° N, 42.841° E; 2049 m a.s.l.; 11 Jun. 2019; S. Bot leg.; SBA, SB.003093 • 1 ♀; Borjomi N.P. ; 41.8181° N, 42.8316° E; 2004 m a.s.l.; 11 Jun. 2019; J.H. Skevington leg.; CNC, CNC1386260 • 1 ♀; Borjomi N.P. ; 41.82° N, 42.84° E; 2100 m a.s.l.; 11 Jun. 2019; J. van Steenis leg.; JSB, 2019-01.098 , ZFMK-TIS-8009613 • 1 ♂; near Akhalkalak ; 41.4672° N, 43.4337° E; 1476 m a.s.l.; 19 Jul. 2021; S. Bot leg.; SBA, SB.003114 • 21 ♂♂, 1 ♀; Kodiani ; 41.7305° N, 43.3537° E; 2160 m a.s.l.; 10 May 2023; F. Van de Meutter leg.; FMT • 15 ♂♂; Kodiani ; 41.7300° N, 43.3485° E; 2080 m a.s.l.; 10 May 2023; W. Opdekamp leg.; WOR, A004 to A007 , A011 , A012 , A029 to A032 , A036 , A037 , A042 , A044 , A046 • 3 ♀♀; same data as for preceding; WOR, A002 , A008 , A010 .

RUSSIA – North Ossetia-Alania • 1 ♀; W of Digoria, Chefandzar mire in Urukh River valley ; 42.9186° N, 43.5149° E; 2289 m a.s.l.; 2–3 Jun. 2018; A. Przhiboro leg.; yellow plates; ZFMK, ZFMKDIP-00078663 = ZFMK-TIS-8009570 . – Kabardino-Balkaria • 1 ♀; 2–3 km SE of vill. Verkhnyaya Balkaria ; 43.0971° N, 43.4795° E; 1836 m a.s.l.; 7–8 Jun. 2018; A. Przhiboro leg.: yellow plates; ZFMK, ZFMK-DIP-00078650 = ZFMK-TIS-8009593 • 1 ♀; 2–3 km SE of vill. Verkhnyaya Balkaria ; 43.0983° N, 43.4777° E; 1810 m a.s.l.; 7–8 Jun. 2018; A. Przhiboro leg.: yellow plates; DIP-00078655 = ZFMK-TIS-8009599 .

Description

Male

LENGTH. Body 8.5–11.5 mm, wing 6.5–9 mm.

HEAD. Face bare, black, with facial tubercle, slightly pruinose, densely pruinose below lunule, facial tubercle shiny. Parafacia black, pruinose, white pilose, about or almost as wide as length of postpedicel. Clypeus shiny or seldom slightly pruinose, 1.8 to 2.5 times as long as wide. Frontal triangle black, densely pruinose along eye margin and along face, otherwise slightly pruinose, with long black pile. Length of eye contiguity about as long as length of frons. Angle of approximation of eyes ca 90°. Vertical triangle black, shiny, ocellar triangle shiny, long black pilose, sometimes with small yellow pile intermixed. Occiput pruinose, short yellow and long black pilose. Lunule dark orange, with distinct medial arm, separating acetabula. Scape black, anteriorly with black setae; pedicel black, anteriorly with black setae; postpedicel black, rounded, pruinose, about as long as wide; arista black, basally with very short pile. Eyes with relatively sparse but long pile; colour of pile ranging from wholly dark yellow to black in dorsal part and yellow in ventral part.

THORAX. Scutum black, shiny except narrowly anteriorly, finely punctured, with long erect black pilosity, of two lengths in posterior part, anteriorly sometimes with some white pile. Scutellum shiny, with long and short black pile, sometimes also with short white pile, posterior margin with numerous black setae. Pleura black, slightly pruinose, with black pile except with white pile on proepisternum and metasternum and with white pile intermixed on katepisternum; dorsal and ventral pile patches on katepisternum widely separated. Haltere dark yellow to dark brown.

WING. Wing including alula entirely microtrichose, ranging from hyaline to with brown tinge in basal anterior part, veins black.

LEGS. Legs black, or in few specimens basal one-tenth of tibiae yellow. Coxae pruinose, procoxa with black pile, often intermixed with some yellow pile, anteriorly with black setae, sometimes intermixed with a few yellow setae; mesocoxa with black pile and setae, sometimes a few yellow pile or setae; metacoxa with mixed yellow and black pile, black pile often dominating. Trochanters black, with mixed black and yellow pile. Profemur with black pile except a few yellow pile anterolaterally; mesofemur with black pile, basis antero- and posterolaterally with mixed black and yellow pile; metafemur black pilose, posterolaterally with yellow pile, anterolaterally with short black pile and scattered long pile, the basal part of the long pile yellow. Protibia black pilose, anterolaterally yellow pilose; mesotibia black pilose; metatibia black pilose, apical two third of anterolateral side yellow pilose. Protarsus dorsally and posterolaterally black pilose; ventrally and anterolaterally yellow pilose; mesotarsus black pilose; metatarsus dorsally black pilose, ventrally yellow pilose.

ABDOMEN. Terga I–III medially pruinose, laterally shiny, tergum IV shiny except pruinose along anterior margin, medially slightly extending. Pile on terga long and erect, longest along lateral margins, medially adpressed on terga II–IV, colour variable, ranging from mainly yellow to mainly black, at least medially on terga II–III and laterally on tergum I and anterolaterally on tergum II predominantly black. Sternum I pruinose, with yellow pile; sternum II shiny or slightly pruinose, with long erect white pile and some long erect black pile medially; sternum III shiny, laterally and anterolaterally with erect white pile, otherwise with adpressed black or mixed yellow and black pile; sternum IV slightly pruinose, laterally with erect white or mixed black and white pile, medially with adpressed black or black and yellow pile. Genitalia with surstylus about 1.6 times as long as wide, on apical part with field of microtrichia ( Fig. 19D). Ventral lobe of postgonite halfway bent inwards, longer than dorsal lobe, dorsal lobe short and blunt ( Fig. 19C). Apical sclerite of aedeagus with wide and large anterior lobes, lacking posterior lobes.

Female

LENGTH. Body 8–10 mm, wing 7–8 mm.

Similar to the male, except for normal sexual dimorphism and the following characters: frons with mixed yellow and black pile. Dorsal part of occiput shiny. Eye with sparse yellow pile, sometimes eye bare. Scutum with semi-adpressed black pile, sometimes mixed with yellow pile. Posterior margin scutellum with fewer and shorter setae. Terga 2–5 shiny. Terga predominantly with yellow pile except medially on terga II–III, where black.

Morphological variation

In one female specimen (ZFMK-DIP-00066552 = ZFMK-TIS-8006833) the face is pilose.

Genetics

We recovered a cluster (BS = 93.6%) with the single sequence of C. carbonaria Egger, 1860 and the barcodes of C. caucasi sp. nov., C. cynocephala Loew, 1840 and C. abagoensis . While DNA barcodes of C. cynocephala cluster together (BS <90%), DNA sequences of C. caucasi are grouped into three different clusters (BS = 97.7–99.7%), except for three females which are resolved into a different cluster with the barcodes of C. abagoensis (BS = 99.6%).

Biology

Collected between 1400–2860 m a.s.l. on extensive grasslands. Most often found feeding on Caltha palustris , Ranunculus sp. and yellow crucifers.

Distribution

Only known from the Greater and Lesser Caucasus in Georgia and Russia.