Research Article |
Corresponding author: Gunilla Stahls ( gunilla.stahls@helsinki.fi ) Academic editor: Martin Hauser
© 2017 Gunilla Stahls, Anatolij V. Barkalov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ståhls G, Barkalov AV (2017) Taxonomic review of the Palaearctic species of the Cheilosia caerulescens-group (Diptera, Syrphidae). ZooKeys 662: 137-171. https://doi.org/10.3897/zookeys.662.11267
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The Palaearctic species of the Cheilosia caerulescens group (Diptera: Syrphidae) are revised in this work. The species group belongs to the genus Cheilosia subgenus Taeniocheilosia Oldenberg. One new species is described from north Caucasus, Cheilosia (Taeniocheilosia) circassicasp. n. Cheilosia primulae Hering is established as a junior synonym of Cheilosia laeviventris Loew. Four lectotype designations are made. The species of the Cheilosia caerulescens group are redescribed and illustrated, and a table of diagnostic characters and an identification key to species are provided. MtDNA COI barcodes were generated for several specimens of C. (T.) caerulescens Meigen and other Cheilosia (Taeniocheilosia) and Cheilosia s. str. taxa. Parsimony and maximum likelihood analyses did not place the morphologically similar C. hercyniae Loew in the C. caerulescens group but among other Cheilosia (Taeniocheilosia) taxa. The following eight taxa are included in the Cheilosia (T.) caerulescens group of species: Cheilosia armeniaca Stackelberg, 1960, C. caerulescens caerulescens (Meigen, 1822), C. caerulescens calculosa Skufjin, 1977, C. circassica sp. n., C. herculana Brădescu, 1982, C. kerteszi Szilády, 1938, C. laeviventris Loew, 1857, and C. venosa Loew, 1857.
Barcoding, Cheilosia caerulescens, mtDNA COI, taxonomy
Cheilosia Meigen, 1822 (Diptera, Syrphidae) is the largest Palaearctic hoverfly genus with nearly 300 species listed (
The Palaearctic bare eyed and black legged species of the subgenus Taeniocheilosia Oldenburg (as Nigrocheilosia Shatalkin) were revised by
The aim of the present study is to revise the Palaearctic species, to define the members of the C. (Taeniocheilosia) caerulescens group and to redescribe them. We were especially interested in testing the phylogenetic placement of Cheilosia hercyniae Loew, 1857 based on molecular sequences. The taxon belongs to the subgenus. Taeniocheilosia and has bi-colored legs and very slightly infuscated wing crossveins (or with only yellowish wing veins without infuscation), thus partly agreeing with character states of other Cheilosia caerulescens group taxa.
In addition to the morphological studies of the C. (Taeniocheilosia) caerulescens group taxa, mtDNA COI barcodes were obtained for recently collected C. caerulescens specimens, and also for representative taxa of subgenera Taeniocheilosia (including C. (T.) hercyniae), Eucartosyrphus and Cheilosia s. str. These sequence data were analyzed using parsimony and maximum likelihood to explore the placements of the mentioned taxa.
In the material examined, the collections where the specimens are deposited are indicated between square brackets after each specimen. Type localities and holotype-holding institutions are specified for each species. Identification and location labels are indicated with single quotation marks. Handwritten information on labels is indicated.
Terminology follows
The material comprising adult flies consists of dry, pinned specimens from the following museums, institutions and private collections:
Coll. C. Claussen Private collection of Claus Claussen, Germany
Coll. D. Doczkal Private collection of Dieter Doczkal, Germany
Coll. T. Romig Private collection of Tomas Romig, Austria
ISEA Institute of Systematics and Ecology of Animals (earlier BIN Biological Institute), Novosibirsk, Russia
Male genitalia were dissected, macerated in 10% KOH, soaked in water and neutralized with 10% acetic acid, and stored in glycerol in plastic microvials on the same pins as the specimens.
For each species figures are provided for the attributes considered relevant for species recognition. Body length was measured dorsally from the anterior margin of lunula to the tip of the abdomen. Drawings are provided of the male genitalia, the profile of the face and the basoflagellomere for the males; and of the dorsal view of frons and basoflagellomere of the females. The figures of male heads show the distribution of pollinosity and pilosity, in females the distribution of pollinosity. The dorsal aspect of the male head is shown in Fig.
When necessary, a lectotype has been designated and labelled accordingly in order to fix the concept of the taxon in question and to ensure the universal and consistent interpretation of the same.
The distribution given in
DNA was extracted from 1–3 legs of dry pinned or ethanol preserved specimens using the Nucleospin Tissue DNA extraction kit (Machery-Nagel, Düren, Germany) following the manufacturer’s protocols and then re-suspended in 50 µl of ultra-pure water.
The universally conserved primers LCO1490 and LCO2198 (
Labcode | Species | Locality | Sex | EMBL ENA accession |
---|---|---|---|---|
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Cheilosia albipila Meigen | RUSSIA, Caucasus, Krasnodar krai, Guamskoe canyon, 1700m, Kurdzips river area, 20.V.2015, E. Rättel, O. Gerzovsky leg. | Female | LT707495 |
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Cheilosia albitarsis (Meigen) | FINLAND, 66941:34004, N: Sibbo, Hindsby, 13.VI.2009, G. Ståhls leg. | Female | LT707496 |
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Cheilosia caerulescens caerulescens (Meigen) | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 24.IV.2015, G. Ståhls leg. | Male | LT707497 |
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Cheilosia caerulescens caerulescens (Meigen) | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 24.IV.2015, G. Ståhls leg. | Male | LT707498 |
|
Cheilosia caerulescens caerulescens (Meigen) | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707499 |
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Cheilosia caerulescens caerulescens (Meigen) | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707500 |
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Cheilosia caerulescens caerulescens (Meigen) | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707501 |
CNCDB434_11 | Cheilosia caerulescens caerulescens (Meigen) | FRANCE, Haute, Montagne de Lure Jas de Bailles, 1300 m, C. Kassebeer leg. | Female | JN991966 |
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Cheilosia derasa Loew | SLOVENIA, Triglav NP, 46.303°N, 13.762°E, 22.VII.2012, 1520–1685m, S.M. Blank coll. | Female | LT707508 |
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Cheilosia gagatea Loew | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707507 |
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Cheilosia grisella Becker | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 7.VI.2013, A. Vujic leg. | Female | LT707510 |
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Cheilosia hercyniae Loew | MONTENEGRO, Durmitor, 1997, A. Vujic leg. | Female | AY533355 |
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Cheilosia impudens Becker | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 24.IV.2015, G. Ståhls leg. | Male | LT707502 |
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Cheilosia insignis Loew | SERBIA, Tara, Brusnica, 27-IV.2012, Vujić A., Radenković, S., Likov, L. leg. | Female | LT707512 |
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Cheilosia kerteszi (Szilady) | MONTENEGRO, Durmitor, 1997, A. Vujic leg. | Male | AY533344 |
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Cheilosia laeviseta Claussen | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707505 |
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Chelosia longula (Zetterstedt) | FINLAND, 69745:35305, Sb: Kuopio, Kolmisoppi, 19.VIII.2015, G. Ståhls & E. Rättel leg. | Female | LT707514 |
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Cheilosia nigripes (Meigen) | FINLAND, Kesälahti, Pivanka, 12.VI.2005, J. Kahanpää leg. | Female | BOLD process ID FIDIP2504–12 |
|
Cheilosia nivalis Becker | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 7.VI.2013, A. Vujic leg. | Male | LT707509 |
|
Cheilosia pedemontana Rondani | SWITZERLAND, Valais, Rossboden, 46.196058N, 08.026283E, 25.V.2015, 2000m, G. Ståhls leg. | Male | LT707504 |
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Cheilosia personata Loew | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 7.VI.2013, A. Vujic leg. | Male | LT707511 |
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Cheilosia pubera (Zetterstedt) | FINLAND, Rantasalmi 30.V.2015, E. Rättel leg. | Female | LT707506 |
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Cheilosia sibirica Becker | RUSSIA, Altay, Teletskoe lake area, 51°47'29.502N, 87°19'06.11E, 23–25.VI.2013, G. Ståhls leg. | Female | LT707513 |
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Cheilosia schnabli Becker | RUSSIA, Caucasus, Krasnodar krai, near Apscheronsk, 700m, 20.V.2015, E. Rättel leg. | Male | LT707517 |
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Cheilosia scutellata (Fallén) | SPAIN, Grazalema NP, 36°43'03"N, 5°20'06"W, nr puerto Los Alamillos, 800m, 14.VI.2014, G. Ståhls leg. | Male | LT707516 |
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Cheilosia soror (Zetterstedt) | GREECE, Samos island, 37°47.313N, 26°49.412E, 173m, nr Manolates, 14.V.2010, G. Ståhls leg. | Male | LT707515 |
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Cheilosia vicina (Zetterstedt) | SWITZERLAND, Valais, nr Simplon Dorf, 1650 m, 46°12'19"N, 8°02'25"E, 24.IV.2015, G. Ståhls leg. | Male | LT707503 |
|
Pelecocera (Chamaesyrphus) scaevoides (Fallén) | FINLAND, N: Raseborg, Ekenäs, 14.VIII.2012, G. Ståhls & E. Rättel leg. | Female | AY533320 |
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Ferdinandea ruficornis (Fabricius) | RUSSIA, Primorsk region, Sikhote-Alin reserve, nr Khanov camp, 44°53'72"N, 136°20'13"E, 1.IX.2014, G. Ståhls & E. Rättel leg. | Female | LT707518 |
Full-length mtDNA COI barcodes were generated for 25 Cheilosia specimens. We additionally included shorter barcodes (450 bp) of the species Cheilosia kerteszi and C. hercyniae, and one barcode of C. caerulescens was retrieved from the Barcoding of Life Database (Table
Parsimony analyses for all sequence datasets were performed in NONA (Goloboff, 1999) spawn with the aid of WINCLADA (Nixon, 2002) using the heuristics search algorithm with 1000 random addition replicates (mult*1000), holding 100 trees per round (hold/100), maxtrees set to 100 000 and applying tree-bisection–reconnection branch swapping. Nodal support for each tree was assessed using non-parametric bootstrap resampling with 1000 replicates using WINCLADA. Maximum Likelihood (ML) analysis was done in MEGA version 6 using the General Time Reversible (GTR) model with gamma distributed rates among sites based on model-testing results as implemented in the software (
The Cheilosia (Taeniocheilosia) caerulescens group of species can be distinguished from all other Cheilosia by the combination of the following characters: eye bare, distinctly darkened cross veins of wing, comparatively broad body, usually bi-colored legs, and characteristics of male genitalia structures: superior lobes with distinct left and right process, apical sclerite of aedeagus elongated in lateral direction (Figs
Diagnostic characters of species of the Cheilosia caerulescens group and Cheilosia hercyniae.
armeniaca | c. caerulesc | c. calculosa | herculana | hercyniae | kerteszi | laeviventris | teberda | venosa | |
---|---|---|---|---|---|---|---|---|---|
Antennal pits | confluent | confluent | separated | confluent | separated | separated | ≈separated | confluent | confluent |
Arista | pilose | pilose | bare | pilose | pilose | pilose | pilose | pilose | pilose |
Pilosity on vertical triangle | whitish | black | black | black and some pale | black | some pale | black | white | black |
Black bristles on post-alar callus | absent | present | present | absent | present | present | present | absent | present |
Hair patches on katepisternum | connected | connected | connected | connected | widely divided | connected | divided | connected | narrowly connected |
Distribution of microtrichia on wing | with some bare areas | uniformly microtrichose | uniformly microtrichose | with some bare areas |
uniformly microtrichose | uniformly microtrichose | uniformly microtrichose | uniformly microtrichose | uniformly microtrichose |
R4+5 of wing | straight | slightly curved | straight | straight | straight | straight | straight | straight | curved |
Mesofemur: apico-posterior area | pale pile | pale pile, few black pile | black pile | pale pile | pale pile, few black pile | pale pile | black pile | pale pile | black pile |
Metafemur: antero-basal area | long pale pile | long pale pile | long pale pile | long pale pile | pale pile | long pale pile | short black pile |
long pale pile | black pile of different lengths |
1 | Cell bm and cell cup of wing with distinct areas bare of microtrichia (Fig. |
2 |
– | Cell bm of wing completely microtrichose (Fig. |
3 |
2 | Face with dense pollinosity, frons with yellow pile mixed with some black pile, hypopygium Fig. |
|
– | Face with very slight pollinosity, frons with only pale pile, hypopygium Fig. |
armeniaca Stackelberg, 1960 |
3 | Apical half of posterior surface of mesofemur and basal part of anterior surface of metafemur with long black pile | 4 |
– | Apical half of posterior surface of mesofemur and basal part of anterior surface of metafemur with long light pile (but metafemur only apico-ventrally sometimes with a few black pile) | 5 |
4 | Hind margin of scutellum without black bristles or bristle-like pile. R4 + 5 of wing distinctly curved (Fig. |
venosa Loew, 1857 |
– | Hind margin of scutellum with black bristles or bristle-like pile. R4 + 5 of wing not curved (Fig. |
laeviventris Loew, 1857 |
5 | Basoflagellomere of male with distinct anterodorsal angle, completely bright orange or orange with darkened dorsal corner (Figs |
hercyniae Loew, 1857 |
– | Basoflagellomere of male without anterodorsal angle, reddish brown to black (Figs |
6 |
6 | Abdominal tergites with erect yellow pile only | 7 |
– | Abdominal tergites with erect to semi-erect yellow pile laterally, medially at least on tergite III with some black pile | 8 |
7 | Antennal pits separated, vertical triangle with black and a few yellow pile, scutum with yellow and black pile, postalar callus with few black bristles. Hypopygium as on Fig. |
kerteszi Szilády, 1938 |
– | Antennal pits confluent, all pile on body white, postalar callus without any bristles Hypopygium Fig. |
circassica sp. n. |
8 | Basal 1–3 segments of pro- and metatarsi dorsally yellow, arista appearing bare (Fig. |
caerulescenscalculosa Skufjin, 1977 |
– | Basal 1–3 segments of pro- and metatarsi dorsally black or dark-brown, arista with short pile (Fig. |
caerulescenscaerulescens (Meigen, 1822) |
Cheilosia armeniaca Stackelberg, 1960: 439.
Cheilosia
armeniaca
:
East slope of Mountain Kapudschikh, Armenia.
Holotype, ♂, pinned, in
♂: Face in frontal view slightly divergent from level of antennal insertion to lower mouth edge, covered with very weak narrow strip of pollinosity (Fig.
Size. Body length 8.5 mm.
Georgia 1♂; ‘Georgia, Gornaia Tushetia, Omalo village 30.VII.1959 (Zaitsev)’ [
Caucasus: Armenia, Georgia*.
Female unknown.
Syrphus caerulescens Meigen, 1822: 295.
Chilosia
coerulescens
:
Cheilosia
caerulescens
:
Nigrocheilosia
caerulescens
:
Österreich [Austria].
Lectotype, ♂, in
Male: Fig.
Female: Fig.
Size. Body length 6.5–12 mm.
Switzerland 2 ♂, 2 ♀ Zermatt, 1 600–1 700 m, 30.VII.1964 (v.d. Goot; Lucas) [
Austria, Belgium, Czech Republic, France, Germany, Great Britain, Italy, Netherlands, Montenegro, Poland, Romania, Spain, Slovakia, Switzerland.
Color of pile on scutum varies from almost yellow with some black pile to yellow with broad stripe of black pile between wing bases (Fig.
Cheilosia caerulescens calculosa Skufjin, 1977:57.
‘Lipetzk Region, Galichia Gora reserve’ (Russia).
Holotype, ♂, in
♂: Face in frontal view slightly divergent from level of antennal insertion to lower mouth edge, slightly elongated, shining with stripe of pollinosity. Facial knob moderate, shining (Fig.
Female: Face as in male, parafacia shining, narrow, about 1/3 of width of basoflagellomere. Frons comparatively broad with two furrows (Fig.
Size. Body length 9–10.2 mm.
Russia 4 ♂, 2 ♀ ‘Lipetzk Region, Galichia Gora reserve, 24–28.IV.1966, Kuznetzova’ [
European part of Russia.
We treat the taxon as subspecies until evidence to the contrary is presented.
Holotype, ♂, pinned, with genitalia dissected in microvial, in
Paratype, 1 ♂, Teberdinskij reserve, mountain Malaia Khatipara, 1400–2000 m 14.VII.1982 (Lukashova) (ISEA).
♂: Face in frontal view slightly divergent from level of antennal insertion to lower mouth edge, with weak narrow strip of pollinosity (Fig.
Size. Body length 9 mm.
The specific name means “from Tscherkessia” in Latin and English.
No additional material available.
Russia (Caucasus).
Female unknown.
Cheilosia herculana Brădescu, 1982: 13.
Nigrocheilosia
herculana
:
“Roumaine, Carpates Meridionales, Monts Mehedinti, Baile Herculane, Vallee du ruisseau Feregari” [Herculane, Romania].
Holotype, male, in
♂: Face in frontal view slightly divergent from level of antennal insertion to lower mouth edge, shining, with very weak stripe of pollinosity, lower part somewhat protruded (Fig.
♀: Face and parafacia as in the male. Frons shining, coarsely punctated, with white erect pile, and mixed with black erect pile on posterior part. Frontal furrows moderate (Fig.
Size. Body length 10–11 mm.
No additional material available.
Romania, Montenegro, FYR Macedonia.
Cheilosia
hercyniae
Loew, 1857:596;
Chilosia
hercyniae
:
Nigrocheilosia
hercyniae
:
“Der Hartz, Oesterreich” [sic][Austria].
Lectotype, ♂, pinned, in MNB, here designated to fix the concept of Cheilosia hercyniae Loew and to ensure the universal and consistent interpretion of the same. The original description concerns only the male sex. The lectotype is labelled: ‘Austria, Schiner’, ‘Coll. H. Loew’, ‘Zool. Mus., Berlin’, ‘Lectotype Cheilosia hercyniae Loew, Ståhls & Barkalov des.’.
♂: Face in frontal view moderately divergent from level of antennal insertion to lower mouth edge, with slight to moderate pollinosity, but facial knob shining. Facial knob moderately protruding (Fig.
♀: Face and parafacia as in male. Basoflagellomere big, bright orange-yellow, quadratic, with a long (≈ 1/3 of the length of antenna) groove on the inner ventral side (Fig.
Size. Body length 8–11 mm.
Italy 1 ♂ Italy, Val Gardena, Col Raiser-n. Regensb. Hütte, 2150–2200 m, 46°35'N 11°44'E, 22.06.2013, leg. T. & W. Romig [coll. Romig]; France 1 ♂ ‘Le Lautaret, 10.VII.24’ [
Austria, Czech Republic, France, Germany, Italy, Montenegro, Poland, Romania, Spain, Switzerland,
Chilosia kerteszi Szilády, 1938:138.
Cheilosia
kerteszi
:
Nigrocheilosia
kerteszi
:
“Ostungarn, Szászka und Rév” [Romania].
Type material could not be located, apparently lost.
♂: Face in frontal view slightly divergent from level of antennal insertion to lower mouth edge, shining with very slight pollinosity, lower part somewhat protruded (Fig.
♀: Face and parafacia as in the male. Frons coarsely punctated, with white erect pile, and also with black erect pile on posterior part (Fig.
Size. Body length 10–11 mm.
Serbia 1 ♂, 1 ♀ ’Serbija, Klisura peka, 3.V.1993, leg. Milankov’ [
Montenegro, Romania, Serbia*.
Cheilosia
laeviventris
Loew, 1857:602;
Chilosia
laeviventris
:
Chilosia primulae Hering, 1944:117. Type locality: ‘Ebenstein, Hochschwabgruppe’ [Austria]. Syn. n.
“Oesterreich” [sic] [Austria].
C. laeviventris: Lectotype, ♂, pinned, with genitalia dissected in microvial, in
C. primulae: Lectotype, ♂,
Description. ♂: Face in frontal view moderately divergent from level of antennal insertion to lower mouth edge, with pollinosity, lower part of face clearly protruded (Fig.
♀: Face as in the ♂. Frons with pollinosity laterally, otherwise shining, pile mixed black and white (Fig.
Size. Body length 8–11 mm.
Austria 1 ♂, 2 ♀ ‘Österreich, Tirol, Seefelder Joch, 2050 m, 15.VII.1969, v. d. Goot & Lucas’ [ZMA]; Germany 5 ♂ ‘Alpen Oberstdorf, Nebelhorn, Koblat, 1 920–2 220 m, 4.7.1994, D. Doczkal’ [coll. D. Doczkal].
Austria, France, Germany, Italy, Romania, Switzerland.
Cheilosia
venosa
Loew, 1857:603;
Chilosia
venosa
:
‘Oesterreich’ [sic] [Austria].
Lectotype ♂, pinned, with genitalia dissected in microvial, in MNB, here designated to fix the concept of Cheilosia venosa Loew and to ensure the universal and consistent interpretion of the same. The original descriptions is only for the male sex. The lectotype is labelled: ‘Austria, Schiner’ [handwritten, faded inc], ‘Coll. H. Loew’, ‘Zool. Mus., Berlin’, ‘Lectotype Cheilosia venosa Loew, Ståhls & Barkalov des.’.
♂: Face in anterior view moderately divergent from level of antennal insertion to lower mouth edge, with lower part not very prominent, with band of pollinosity (Fig.
Scutum densely punctated, shining, with long, erect yellow pile, medially a transverse band of predominantly black pile. Scutellum on hind margin without (occasionally with some) black bristles. Postalar callus with two bristles. Pleura pollinose, with long black and yellow pile. Dorsal and ventral pile patches of katepisternum only narrowly connected anteriorly. Legs black, knees sometimes yellow, tibia sometimes black ringed. Apical half of posterior surface of mesofemur and basal part of anterior surface of metafemur with long black pile (Fig.
♀: Face shining with fine pollinosity on the sides. Parafacia comparatively narrow, pollinose. Frons moderately broad, shining (Fig.
Size. Body length 9–11 mm.
Additional material studied. Austria 1 ♂ ‘Österreich, Tirol, Seefelder Joch, 2 050m, 15.VII.1969, v.d. Goot’ [in ZMA], 1 ♂ ‘Austria, Brauer’ [MNB], 1 ♂ ‘Austria, Schiner’ [MNB]; Switzerland 1 ♀ ‘Helvetia, GR, Lenzerheide, Parpaner Rothorn, 2 850 m, 14.VII.96, B. Merz’ [
Austria, Italy*, Germany, Romania, Switzerland*.
COI barcodes were obtained of 658 bp sequence for 27 Cheilosia specimens and two outgroups (see Table
Parsimony analysis of the COI data resulted in two equally parsimonious trees of length 494 steps, with Consistency Index of 0.52 and Retention Index of 0.69, and the strict consensus is presented in Fig.
The Cheilosia (Taeniocheilosia) caerulescens species group presently comprises eight species. Their distribution is predominantly in the mountainous areas of Europe and Caucasus, but C. caerulescens calculosa is known from chalk slopes at the of the river Don in Lipetsk region (Russia) and C. caerulescens caerulescens is widely distributed in central Europe including both lowland and mountainous areas. The larval host plant is known for C. caerulescens caerulescens, the larvae are phytophagous mining the leaves of species of genus Sempervivum (
We consider the C. caerulescens calculosa subspecies as a relict form. According to
Neither the parsimony analysis nor the ML analysis resolved Cheilosia hercyniae among the included C. caerulescens group species, but among other sg. Taeniocheilosia taxa in congruence with conclusions based on morphological characters. C. hercyniae shares the character of infuscated wing cross-veins and bi-coloured legs with the members of the Cheilosia caerulescens group, but differs from all C. caerulescens group species in having a bright orange-yellow basoflagellomere and hair patches of katepisternum widely separated. In male genitalia C. hercyniae is similar to some sg. Taeniocheilosia species, e.g. Cheilosia pedemontana, C. gagatea and C. faucis (Becker, 1894) in the shape of the superior lobe.
The COI barcode of Cheilosia kerteszi is not full length and is very similar to the COI of the included C. caerulescens samples, but not identical to anyone of them. Identical or near identical COI barcodes of closely related Eristalinae species has also been recorded for Merodon species groups, see e.g.
The studied group can be regarded as a morphologically intermediate group between the subgenera Cheilosia (Neochilosia Barkalov) and Cheilosia (Eucartosyrphus Barkalov), as the colour of the legs of its members is similar to that of the latter, but the presence of a large plate on the left process of superior lobe of hypandrium indicates an affiliation of this group to the subgenus Neochilosia.
We thank the curators and private collection owners for their most generous longstanding loans of material, and Prof. Ante Vujić (University of Novi Sad, Serbia) for unpublished distributional data. Financial support from the Entomological Society of Helsinki and Russian Foundation for Basic Research, grant number 16-04-00194-a is gratefully acknowledged.