Cheilosia luteicornis ( Zetterstedt, 1838 ) Bot & Ståhls & Bygebjerg & Doczkal & Vujić, 2025

Bot, Sander, Ståhls, Gunilla, Bygebjerg, Rune, Doczkal, Dieter & Vujić, Ante, 2025, Revision of the European species of the subgenus Neocheilosia Barkalov (Diptera, Syrphidae: Cheilosia), European Journal of Taxonomy 997, pp. 1-27 : 10-14

Cheilosia luteicornis ( Zetterstedt, 1838) stat. nov.

Figs 2 , 5A, D, F

Eristalis luteicornis Zetterstedt, 1838: 612 .

Type localities: “Juckasjarvi; Pello, Lapponiae Tornensis; Lycksele Lapponiae Umensis” [ Juckasjärvi and Lycksele in Swedish Lapland, and Pello in Finnish Lapland] (lectotype, selected by Claussen, designated here, ♀, MZLU).

Eristalis lineata Wahlberg in Zetterstedt, 1843.Type locality: “ad Holmiam” [surroundings of Stockholm, Sweden] (lectotype, ♂, NRM, examined by Claussen). Syn. nov.

Cheilosia morio – Schiner 1862: 283. — Becker 1894: 448. — Hellén 1912: 157. — Sack 1930: 39; 1932: 88. — Séguy 1961: 43. — Bańkowska 1963: 125. — Stackelberg 1970. — van der Goot 1981: 168. — Violovitsh 1983: 85. — Mutin & Barkalov 1999: 436 (in part). — van Veen 2004: 65–66, fig. 174 (in part). — Mazánek 2006: 83. — Haarto & Kerppola 2007: 254 (in part). — Barkalov & Ichige 2016: 571–580. — Bot & Van de Meutter 2019: 58, 233. — Heimburg et al. 2022: 169.

Cheilosia “ morio A” – Bartsch et al. 2009: 57, 106. — van Steenis 2011: 188.

Cheilosia luteicornis – Nilsson et al. 2012: 148. — Bot & Van de Meutter 2023: 50, 227.

Material examined

FINLAND – Åland • 1 ♀; Åland, Lemland , Flaka ; 60.006127° N, 20.138916° E; 20 May2012; Raekunnas leg.; http://id.luomus.fi/ HT.3488 ; MZH . – Pohjois-Pohjanmaa • 1 ♀; Rovaniemi ; 66.27° N, 25.11° E; 19 June 1951; Stenberg leg.;http://id.luomus.fi/ GV.93913 ; MZH. – South Hame • 1 ♀; Hattula ; 61.03° N, 24.27° E; 1906; Wegelius leg.; http://id.luomus.fi/ GV.93924 ; MZH 1 ♀; Forssa ; 60.85° N, 23.62° E; 12 May 1962; Nylund leg.; http://id.luomus.fi/ GV.93910 ; MZH • 1 ♀; Forssa ; 60.85° N, 23.62° E; 14 May 1964; Käpylä leg.; http://id.luomus.fi/ GV.93920 ; MZH • 1 ♂; Somero ; 60.63 ° N, 23.46° E; 21 May 1964; Maaniitty leg.; http://id.luomus.fi/ GV.93916 ; MZH . – South Karelia • 1 ♂; Kotka, Mussalo ; 60.455875° N, 26.906058° E; 17 May 1918; Ulvinen leg.; http://id.luomus.fi/ GV.23565 ; MZH • 1 ♂; Hamina ; 60.67577° N, 27.079224° E; 10 May 1964; Tiensuu leg.; http://id.luomus.fi/ GV.93911 ; MZH • 1 ♀; same data as for preceding; http://id.luomus.fi/ GV.93921 . – Uusimaa • 2 ♀♀; Loviisa ; 60.44° N, 26.03° E; Nordström leg.; http://id.luomus.fi/ GV.93922 , http://id.luomus.fi/ GV.93915 ; MZH • 1 ♀; Helsinki ; 60.191° N, 24.875° E; Johansson leg.; http://id.luomus.fi/ GV.93912 ; MZH • 1 ♀; Helsinki ; 60.19° N, 25.02° E; Tuomikoski leg.; http://id.luomus.fi/ GV.93927 ; MZH • 1 ♂; Helsinki ; 60.19° N, 25.02° E; Tiensuu leg.; http://id.luomus.fi/ GV.93909 ; MZH • 1 ♀; Vantaa ; 60.27° N, 24.96° E; 1 Apr.– 31 May 1906; Frey leg.; http://id.luomus.fi/ GV.93907 ; MZH • 1 ♂; Espoo, Bodom träsk ; 60.256° N, 24.665° E; 16 May 1932; Frey leg.; http://id.luomus.fi/ GV.93923 ; MZH • 1 ♀; Helsinki, Munksnäs ; 60.198° N, 24.874° E; 6 May 1937; Hellén leg.; http://id.luomus.fi/ GV.93917 ; MZH • 1 ♀; Helsinki ; 60.191° N, 24.875° E; 25 May 1942; Frey leg.; http://id.luomus.fi/ GV.93926 ; MZH • 2 ♀♀; Loviisa, Vahterpää ; 60.369558° N, 26.462275° E; 10 May 1975; Albrecht leg.; http://id.luomus.fi/ GV.23567 , http://id.luomus.fi/ GV.23566 ; MZH • 1 ♀; Loviisa, Vahterpää ; 60.369327° N, 26.407907° E; 4 May 1975; Albrecht leg.; http://id.luomus.fi/ GV.23568 ; MZH . – Varsinais-Suomi • 1 ♀; Varsinais-Suomi, Eriksberg ; 60.374° N, 23.296° E; von Bonsdorff leg.; http://id.luomus.fi/ GV.93914 ; MZH • 1 ♀; Lohja ; 60.26° N, 24.01° E; 6 May 1918; Lindberg leg.; http://id.luomus.fi/ GV.93918 ; MZH • 1 ♀; Salo ; 60.189835° N, 22.876551° E; 17 May 1944; Hellman leg.; http://id.luomus.fi/ GV.21350 ; MZH .

GERMANY – Baden-Württemberg • 1 ♀; Baden-Württemberg, Schwarzwald, Rinken ; 15 May 1992; Stuke leg.; CNC Diptera 101716 • 1 ♀; Baden-Württemberg, Schwarzwald , SE of Todtnauer Hütte; 15 May 1992; Stuke leg.; CNC Diptera 101715 . – Lower Saxony • 1 ♀; Lopautal; 12 Apr. 1991; Kassebeer leg.; CNC Diptera 101818 .

NETHERLANDS – Drenthe • 1 ♂, 1 ♀; Drouwenerveld; 52.957° N, 6.766° E; 21 Apr. 2016; Bot leg.; SBA • 1 ♂, 2 ♀♀; Drouwenerveld ; 52.957° N, 6.765° E; 6Apr. 2019; Bot leg.; SBA • 1 ♀; Drouwenerveld ; 52.957° N, 6.765° E; 17 Apr. 2019; Bot leg.; SBA • 1 ♂; Drouwenerveld ; 52.957° N, 6.763° E; 5 Apr. 2020; Bot leg.; SBA • 1 ♂; Drouwenerveld ; 52.952° N, 6.770° E; 23 Mar. 2022; Bot leg.; SBA .

The molecular specimens are listed in Table 2 .

Description

Male

LENGTH. Body 9.1–12.0 mm, wing 8.1–9.1 mm.

HEAD. Eye with brownish hairs. Anterior eye angle ca 110°–120°. Frons swollen, with a shallow median furrow, greyish-brown pruinose, with long, erect black hairs. Ocellar triangle about equilateral, with long black hairs. Gena wide, viewed obliquely from below about as wide or slightly wider than oral cavity. Face wide, ratio of width of face at level of facial tubercle to maximum width of head = 0.53– 0.58: 1; face faintly pruinose, with a broad fascia of dense pruinosity just below base of antennae. Sides of face not haired. Parafacia at level of facial tubercle about half as wide as 3 rd antennal segment, with short black hairs. Facial surface at sides just above posterior tentorial pits weakly convex. Lunule dark-brown to black. Antenna with scape and pedicel usually black, 3 rd antennal segment usually reddish, but partly to entirely brownish to black in some specimens. Arista usually black, practically bare.

THORAX. Scutum faintly pruinose, anterior half with a pair of pale pruinose vittae, best visible if viewed from behind; in well preserved specimens two less distinct lateral vittae are perceptible; scutal hairs long black, erect, of about even length; hairs of scutellum similar to those of scutum, scutellum without distinct marginal setae, but occasionally with some marginal hairs slightly stronger than on disc. Subscutellar fringe black and long. Pleurae with long black hairs on posterior anepisternum, anepimeron and on katepisternum, dorsal and ventral katepisternal hair patches confluent.

WING. Membrane entirely microtrichose, more or less brownish tinged, especially so in anterior half; veins dark, basal half of RS usually without long dark setulae; calypter whitish to yellowish, with orange or brownish rim, marginal fringe on dorsal lobe partly with black setulae. Haltere with brownish stem and black knob.

LEGS. Legs black, but basal 1/3 of pro- and metatibia, basal 2/5 of mesotibia and extreme apices of femora reddish-yellow, rarely also extreme apices of tibiae yellow; hairs of femora nearly all black, but with a set of yellow hairs posteriorly on metafemur; ventral surface of metafemur with black setulae on basal 2/3, apical 1/3 with a set of antero-ventral black hairs. Tibiae with anterior surface and basal part of ventral surface of protibia and ventral and posterior surface of metatibia with short reddish-yellow hairs, tibiae otherwise with mixed black and yellow hairs. Tarsi with short black hairs or mixed black and reddish-brown haired dorsally, ventral surface of pro- and metatarsi usually reddish-brown haired, or intermixed with black hairs. Tarsi of mesolegs ventrally with black setulae.

ABDOMEN. Tergites entirely brownish pruinose, densely on disc, less densely on sides of tergites 1–3 and on tergite 4 (best seen when viewed obliquely from front); tergites 1–3 long yellow pilose on disc, sides of tergites 1–3 and tergites 4 with long black hairs. Sternites faintly greyish-brown pruinose; sternite 1 predominantly yellow haired, often with some black hairs intermixed medially and along posterior margin; base of sternite 2 and sides of sternites 2–4 usually with long black hairs, hairs on median parts of sternites 2–4 more or less appressed, yellow and/or black to varying extents.

GENITALIA. Right and left surstylus and gonostyli slightly asymmetrical; ventral margin of surstylus with a shallow basal convexity; hypandrium in lateral view about 1.4 times as long as wide; sclerite of distiphallus broadly fused dorsally, with long dorsal lobes.

Female

LENGTH. Body 9.5–12.0 mm; wing 8.0– 9.5 mm.

The ♀ differs from the ♂ in the following characters: hairs much shorter and predominantly pale yellowish-brown.

HEAD. Hairs of eyes short, about 1/4 or less width of postpedicel. Frons exceptionally wide, at level of lunule about 0.45 times as wide as maximum width of head, with a shallow transverse sulcus at level of about lower 1/3 of frons, and with a more or less faint median furrow between lunule and front ocellus; lateral channels narrow, widening from inner dorsal corner of eye towards transverse sulcus, enclosing a small semicircular area of dense grey pruinosity at about median 1/3 of frons; dorsal portion of frons, between lateral channels, transverse sulcus and ocellar triangle and a small area on each side of antennal base more or less shining, remaining parts of frons more or less pruinose; hairs of frons erect, slightly longer than half width of 3 rd antennal segment, varying in colour from predominantly yellow to predominantly black. Occiput dorsally much wider than in male, faintly grey pruinose, with short yellow hairs, or with a few black setulae intermixed dorso-laterally. Gena with long yellow hairs. Face not haired, at level of facial tubercle almost 0.5 times as wide as maximum width of head, faintly grey pruinose; parafacia at level of facial tubercle about as wide as diameter of protibia, pale pruinose and with short yellow hairs. 3 rd antennal segment larger than in male, most often bright orange, or with a black apico-dorsal rim.

THORAX. Scutum and scutellum less densely pruinose, but with pale pruinose sub-median vittae anterior on scutum, usually distinct; hairs clearly unequal in length, erect, predominantly yellow, intermixed with scattered, somewhat longer black hairs; scutellum usually with 6–10 black marginal setae, sub-scutellar fringe short and yellow. Pleurae grey pruinose, with yellow hairs, but hairs shorter and less dense than in male. Calypter whitish, with orange rim and yellow fringe. Haltere with brownish stem and yellowish capitulum.

LEGS. Legs black, but basal 1/3 of pro- and metatibia, and basal 2/5 of mesotibia, and often extreme apices of tibiae and femora reddish-yellow; femora predominantly with yellow hairs, but apices anteriorly and dorsally with short appressed black hairs, posteriorly occasionally with a few longer, thin black setae; ventral surface of metafemur basally without black setulae.

ABDOMEN. Tergites entirely but faintly grey pruinose, especially tergites 2–3 on disc much less pruinose than in male, hairs of tergites entirely yellow, short, erect. Sternites greyish pruinose to varying extents, from entirely matt to slightly shining, with short yellow hairs; hairs erect on sternites 1–2 and on anterior corners of sternite 3, remaining hairs more or less appressed.

Distribution

Austria (H. Heimburg pers. com.), Belgium, Bosnia and Herzegovina, Bulgaria, Czechia, Finland, France, Germany, Italy, Lithuania, Montenegro, Netherlands, Norway, Poland, Serbia, Slovenia, Sweden, Switzerland, Ukraine.

Distribution reported here for Belgium and Switzerland were not reported before in the IUCN Red List assessment ( Vujić & Likov 2021).

Differential diagnosis

Very similar to Cheilosia morio , but differing as follows: sides of face not haired. The parafacia width is about half of the width of the postpedicel. Face and frons are a little less wide than in C. morio . The basal 1/3–2/5 of the tibiae are yellow in both sexes. Calypter is pale yellowish, fringe in the male partly dark brown. ♀ with scutal pilosity of unequal length, with numerous black hairs intermixed. ♂: abdominal tergites 2–3 at least partly yellow haired on disc, tergite 3 often predominantly yellow haired. Genitalia: surstylus with a shallow basal convexity; hypandrium about 1.4 times as long as wide.

Remarks

Zetterstedt received the description of “ Eristl. lineata nov. spec. ♂ ” in a letter from P. Wahlberg, but he did not study the underlying specimen(s), nor other specimens of E. lineata (1843: 807–808). Subsequently Zetterstedt (1849: 3173, in a note under “31. E. melanopa ”) synonymized E. lineata under his C. morio . Among the Cheilosia materials in the Wahlberg and Boheman collections, now incorporated in the general Diptera collection of the NRM (H. Bartsch personal communication), the following historical specimens under the name Cheilosia morio could be located: 1) Wahlberg collection: 3 ♀♀ C. luteicornis , 1 ♀ C. morio ; the specimens are without locality and other data but marked by a small coloured tag. These specimens cannot be syntypes, because of the female gender. 2) Boheman collection: under the name C. morio , there are 1 ♂ and 2 ♀♀ from “Holmiae” (= Stockholm), collected by Wahlberg and labelled by Boheman “Hlm./P.Wg.”. The label of the male agrees well with the type locality and the characters of the specimen agree with those given in the original description of E. lineata Wahlberg , and it is here accepted as the lectotype.

Figures

Fig. 2. Cheilosia luteicornis (Zetterstedt, 1838) (SBA); collected in the Netherlands. A. ♂; habitus dorsal view; body length 10 mm. B. ♂; head lateral view; head height 3.2 mm. C. ♂; head anterior view; head height 3.2 mm. D. ♀; head lateral view; head height 2.5 mm. E. ♀; head anterior view; head height 2.5 mm. Not to scale.

Fig. 5. Cheilosia sp., male terminalia. A–E. Left superior lobe. A. C. luteicornis (Zetterstedt, 1838). B. C. morio (Zetterstedt, 1838). C. C. barovskii Stackelberg, 1930. D. C. luteicornis. E. C. morio. F–H. Aedeagus with apodeme. F. C. luteicornis. G. C. morio. H. C. barovskii. Scale bar = 0.2 mm.