Merodon opacus Vujic , Likov & Radenkovic, 2020

Vujic, Ante, Likov, Laura, Radenkovic, Snezana, Tubic, Natasa Kocis, Djan, Mihajla, Sebic, Anja, Perez-Banon, Celeste, Barkalov, Anatolij, Hayat, Ruestem, Rojo, Santos, Andric, Andrijana & Stahls, Gunilla, 2020, Revision of the Merodon serrulatus group (Diptera, Syrphidae), ZooKeys 909, pp. 79-158 : 79

Merodon opacus Vujic, Likov & Radenkovic sp. nov. Figs 12A-F , 13A, B , 14H-J , 20C , 21A-D , 31A, B , 32A-C

Diagnosis.

Medium sized (7.2-10.6 mm), short pilose dark species with olive-brown reflection; antennae dark; legs mostly black; basoflagellomere elongated (1.8-2 times as long as wide) obviously concave dorsally; arista short 1.5 times as long as basoflagellomere (Fig. 12A-F ); terga dark (Fig. 21A, B ); metafemur incrassate covered with very short pilosity (Fig. 13A, B ); male genitalia: posterior surstyle lobe with small lateral hump (Fig. 14H, I : bp); apical part of anterior surstyle lobe rhomboid (Fig. 14H : al); lingula medium sized (Fig. 14J : l). Similar to Merodon serrulatus from which it differs in dark tergum 2 (in M. serrulatus with small pale lateral maculae). Related to M. hirsutus from which can be distinguished by frons covered with dense microtrichia (Fig. 20C ) (mostly shiny in M. hirsutus ), shorter dorsolateral and ventral pile on metafemur (Fig. 13A, B ), and shorter and more adpressed pile on terga in females (Fig. 21D ). Morphologically related to M. defectus sp. nov. from which can be distinguished by dark tergum 2 (in M. defectus sp. nov. tergum 2 with yellow-orange lateral maculae). Additionally, differs from M. defectus sp. nov. by posterior surstyle lobe with developed lateral hump (Fig. 14I : bp), reduced in M. defectus sp. nov. (Fig. 14B : bp).

Description.

Male. Head. Antennae black to dark brown; basoflagellomere elongated 1.8-2 times as long as wide, and 2.3 times as long as pedicel, concave dorsally with acute apex; large fossette dorsomedial and dorsolateral (Fig. 12A-C ); arista dark and thickened at basal one third, covered with dense microtrichia, 1.5 times as long as basoflagellomere; face and frons black with gray microtrichia, face covered with dense whitish gray, and frons with yellowish gray pile; oral margin microtrichose with shiny lateral areas; lunule shiny black, bare; vertex covered with microtrichia (Fig. 20C ); vertex isosceles, with long, pale whitish yellow pile, in some cases mixed with few black pile on the ocellar triangle; ocellar triangle equilateral; eyes covered with dense pile; occiput with gray-yellow pile, covered with a dense, gray microtrichia; eye contiguity ca. 10-12 facets long; vertical triangle: eye contiguity: frons = 1.2: 1: 2.

Thorax. Scutum and scutellum black with bronze luster, covered with dense, erect, yellow pile; scutum at wing basis with short black pile; scutum with two or more microtrichose vittae, anteriorly connected and posteriorly reaching the scutellum; scutum dull; posterodorsal part of anterior anepisternum, posterior anepisternum (except anteroventral angle), anterior anepimeron, dorsomedial anepimeron, and posterodorsal and anteroventral parts of katepisternum with long, pale yellow pile and grayish microtrichia; wings entirely covered with microtrichia; wing veins brown; calypteres yellowish; halteres yellowish, in some specimens with darker capitulum; legs mostly black, except brown tarsi ventrally in some specimens; pile on legs pale yellow; metafemur moderately incrassate, 3.5 times longer than wide; pile on postero- and anteroventral surface very short with few sparse pile, and ca. as one fourth of width of metafemur, approximately the same length as pile on dorsal surface (Fig. 13A ).

Abdomen. Tapering, 1.2 times longer than mesonotum; terga dark brown to black; terga 2-4 each with a pair of white microtrichose, wide, oblique fasciae (on tergum 2 more triangular); pile on terga all yellow (Fig. 21A, C ); sterna dark brown, covered with long whitish yellow pile.

Male genitalia. Apical part of anterior surstyle lobe rhomboid in shape, 1.5 times longer than wide, covered with dense, short pile (Fig. 14H : al); posterior surstyle lobe oval with small basolateral protrusion (lateral hump) (Fig. 14H, I : bp); hypandrium sickle-shaped, without lateral projections; lingula medium sized (Fig. 14J : l).

Female. Similar to the male except for normal sexual dimorphism and for the following characteristics: antennae with rounded tip, basoflagellomere ca. two times longer than wide, fossette dorsal (Fig. 12D-F ); frons with broad microtrichose vittae along eye margins; frons covered with pilosity of variable color, from mostly gray-yellow to predominantly black; ocellar triangle covered with black pile; terga pale pilose, in some specimens terga 2-4 medially with short adpressed black pile; microtrichose fasciae on terga 3 and 4 narrower (Fig. 21B, D ).

Morphological description of the puparium

(Fig. 31A ). Length: 7.5 mm, width: 4 mm; light brown in color; sub-cylindrical; rough integument with larval segmentation persisting as transverse folds and wrinkles; integument covered with small domes and spicules; pronounced segmental sensilla, bearing seta. The dorsal surface of the prothorax with a pair of anterior spiracles , which are more than two times longer than broad at the base, sclerotized, cylindrical in shape, brown in color, apex with two linear spiracular openings (Fig. 32B ). On the anal segment, two different pairs of lappets present: the ventro-lateral pair represented by fleshy papilla with one sensilla bearing a seta and the dorso-lateral pair with a very poorly developed basal papilla, apically divided bearing one sensilla with a long seta on top of each division. Cephalopharyngeal skeleton (Fig. 31B ). Robust mandibles with dark highly sclerotized hooks, without accessory teeth, fused to the external mandibular lobes; the dorsal cornu narrowed, representing almost the whole length of the ventral cornu. Clypeal sclerite sclerotized, tentorium and intermediate sclerites highly sclerotized and apparently fused; ventral cornu elongated and narrow in profile view, wider and more heavily sclerotized at the posterior end, forming the grinding mill of pestle and mortar construction at the posterior end of the cibarium; cibarium at the base, with a clearly sclerotized end. Posterior respiratory process (Fig. 32A ). Brownish, wider than long, very short (barely visible from dorsal view), button shape, base only slightly wider than apex; dorsal and lateral surface covered by a barely visible ornamentation resembling a network. The outline of the spiracular plate sub-elliptical and barely irregular. Spiracular plate with four pairs of sinuous spiracular openings (clearly separated from each other) around two central scars, first pair clearly shorter than the others; three or four very small circular nodules on each side of the surface of spiracular plate in the area of spiracular openings; four pairs of branched inter-spiracular setae emerging on the outward edges of the spiracular plate. Pupal spiracles (Fig. 32C ). Sclerotized, brownish in color, stout, cylindrical in shape, almost as long as broad, slightly tapered, with not heavily rounded prominence at the end (length 0.3 mm) separated by a distance of ca. five times their length. Upper two-thirds of the lateral sides (except for the granularly surfaced apex) covered with irregularly-spaced, oval-shaped domed tubercles, leaving a more or less triangular central area free of tubercles on both ventral and dorsal surfaces; 3-7 radially-arranged spiracular openings on each tubercle. The whole spiracle surface (from the base to the apex) reticulated with a polygonal pattern, more irregular on ventral side, with polygons being noticeably smaller in the apical part. Material examined. Greece, Lesvos Island, Agiassos, C. Pérez-Bañón leg.: 1 larva (L3 instar) buried in the ground of a chestnut forest, 2 Mar 2006; reared, pupa 4 Mar 2006, adult emerged 21 Mar 2006.

Etymology.

Latin adjective opacus (opaque, not transparent), pertains to the dark tergum 2, without reddish yellow lateral maculae.

Distribution.

Merodon opacus sp. nov. has been recorded on the Greek island of Lesvos and in western Turkey (Fig. 7 ).

Ecology.

Preferred environment: forest/open ground; thermophilous and evergreen Quercus forest; Castanea forest, dry Pinus forest; unimproved grassland and tracksides (Fig. 35A ). Flowers visited: Ornithogalum spp. and Potentilla spp. Flight period: March-September.

Type material.

Holotype. Greece • ♂; Lesvos; Polichnitos; 39°05'02"N, 26°09'13"E; 30 Apr. 2008; A. Vujić leg.; FSUNS 03758. Original label: "HOLOTYPE of Merodon / opacus Vujić, Likov et / Radenković sp.n. 2019" [red label], "Greece, Lesvos, / Polichnitos 30.IV 2008. / Leg. A. Vujic", “03758” (See Supplementary file 4: Figure 4B ). Paratypes. Greece, Lesvos • 1 ♂; Ag. Ermogenis; 39°01'07"N, 26°32'44"E; 2 May 2008; A. Vujić leg.; FSUNS 03760 • 1 ♂; Neochori II; 39°01'10"N, 26°20'02"E; 2 May 2016; A. Vujić, J. Ačanski leg.; FSUNS 11396 • 1 ♀; Agiassos; 39°03'00"N, 26°22'60"E; 6 Jun. 2004; M. Kapsali leg.; MAegean • 3 ♀♀; Agiassos; 39°03'00"N, 26°22'60"E; 23 May 2004; A. Kyriakopoulos leg.; MAegean • 1 ♂; same data as for preceding; 24 May 2001; MAegean • 1 ♀; same data as for preceding; MAegean • 1 ♂; Agiassos; 39°03'00"N, 26°22'60"E; Mar. 2006; C. Pérez-Bañón leg.; CEUA • 4 ♂♂; same data as for preceding; 11 Jun. 2005; CEUA • 4 ♂♂; same data as for preceding; 10 Jun. 2005; CEUA • 8 ♀♀; same data as for preceding; CEUA • 4 ♀♀; same data as for preceding; 6 Jun. 2005; CEUA • 4 ♂♂; same data as for preceding; CEUA • 1 ♂; Agiassos; 39°03'09"N, 26°22'57"E; 860 m a.s.l.; 23 May 2004; M. Kapsali leg.; MAegean • 2 ♂♂; 3.5 km S Agiassos; 39°03'09"N, 26°22'57"E; 860 m a.s.l.; 23 May 2004; M. Kapsali leg.; FSUNS 02487, 02503 • 1 ♂; 3.5 km S Agiassos; 39°03'09"N, 26°22'57"E; 860 m a.s.l.; 23 May 2004; A. Kyriakopoulos leg.; FSUNS 03762 • 1 ♀; 3.5 km S Agiassos; 39°03'09"N, 26°22'57"E; 860 m a.s.l.; 23 May 2004; M. Kapsali leg.; FSUNS 03764 • 3 ♀♀; Agiassos; 39°03'17"N, 26°23'50"E; 760 m a.s.l.; 10 Jun. 2004; M. Kapsali leg.; MAegean • 1 ♂; same data as for preceding; 24 May 2004; MAegean • 2 ♂♂; same data as for preceding; A. Kyriakopoulos leg.; MAegean • 1 ♀; same data as for preceding; MAegean • 2 ♀♀; same data as for preceding; 10 Jun. 2004; MAegean • 1 ♀; 3.8 km SSE Agiassos; 39°03'17"N, 26°23'50"E; 760 m a.s.l., 10 Jun. 2004; A. Kyriakopoulos leg.; FSUNS 03763 • 1 ♀; Agiassos; 39°03'45"N, 26°23'30"E; 700 m a.s.l.; 20 May 2004; A. Kyriakopoulos leg.; MAegean • 1 ♀; same data as for preceding; 6 Jun. 2004; M. Kapsali leg.; MAegean • 1 ♂; Agiassos; 39°03'92"N, 26°22'87"E; 27 May 2009; M. Taylor leg.; MZH http://id.luomus.fi/GJ.1133 • 1 ♂; Agiassos; 39°04'09"N, 26°23'17"E; 600 m a.s.l.; 15 May 2004; T. Petanidou leg.; MAegean • 5 ♂♂; Agiassos; 39°04'17"N, 26°22'22"E; Sep. 2009; A. Vujić leg.; FSUNS Č 64, Č 65, Ž 9 to Ž 11 • 10 ♀♀; Agiassos; 39°04'17"N, 26°22'22"E; Sep. 2009; A. Vujić leg.; FSUNS Ž 12 to Ž 19, Ž 28, Ž 29 • 2 ♂♂; Agiassos; 39°04'17"N, 26°22'22"E; 8 Jun. 2009; G. Ståhls leg.; MZH GJ.1139, GJ.1141• 4 ♀♀; same data as for preceding; MZH GJ.1135 to GJ.1138 • 4 ♂♂; same data as for preceding; 25 May 2009; MZH GJ.1140, GJ.1142, GJ.1143, GJ.1145 • 1 ♂; Agiassos; 39°04'25"N, 26°22'35"E; 8 May 2007; G. Ståhls leg.; MZH GJ.1144 • 1 ♀; same data as for preceding; MZH GJ.1126 • 5 ♂♂; same data as for preceding; 30 May 2009; MZH GJ.1119 to GJ.1123 • 2 ♀♀; same data as for preceding; MZH GJ.1124, GJ.1125 • 1 ♂; same data as for preceding; 27 May 2009; MZH • 1 ♂; 39°10'17"N, 26°18'14"E; FSUNS 02504 • 1 ♀; 39°10'17"N, 26°18'14"E; FSUNS 02505 • 3 ♀♀; 39°10'17"N, 26°18'14"E; 4 Jun. 2012; A. Vujić, L. Likov leg.; FSUNS G1747 to G1749 • 1 ♂; Vatousa; 39°13'51"N, 26°01'23"E; 200 m a.s.l.; 28 May 2001; FSUNS • 1 ♀; 2.5 km S Gavathas; 39°14'54"N, 25°58'60"E; 28 Apr. 2010; M. Hull leg.; WML 05042 • 6 ♂♂; near Sikaminea; 39°21'14"N, 26°17'56"E; 11 May 2009; G. Ståhls leg.; MZH GJ.1127 to GJ.1129, GJ.1132, GJ.1134, GJ.1147 • 2 ♀♀; same data as for preceding; 2 Jun. 2009; MZH GJ.1130, GJ.1131 • 2 ♀♀; 5.7 km NW Mantamados; 39°21'19"N, 26°17'52"E; 600 m a.s.l.; 2-10 May 2001; FSUNS 02488, 02507 • 3 ♂♂; Mantamados; 39°21'19"N, 26°17'52"E; 600 m a.s.l.; 10 May 2001; FSUNS • 2 ♀♀; same data as for preceding; FSUNS • 3 ♂♂; same data as for preceding; 17 May 2001; FSUNS • 1 ♀; same data as for preceding; FSUNS • 1 ♂; same data as for preceding; 23 May 2001; FSUNS • 1 ♂; Sikaminia; 39°21'42"N, 26°17'47"E; 10 May 2001; C. Pérez-Bañón, S. Rojo leg.; CEUA • 3 ♂♂; same data as for preceding; 14 May 2001; CEUA • 15 ♂♂; same data as for preceding; 17 May 2001; CEUA • 1 ♀; same data as for preceding; CEUA • 2 ♂♂; Sikaminia; 39°21'44"N, 26°17'49"E; 3 May 2008; A. Vujić leg.; FSUNS 03757, 03759 • 1 ♂; Sikaminia; 39°21'44"N, 26°17'49"E; 2 May 2001; FSUNS 02506 • 1 ♀; Near Lepetimnos; 39°21'47"N, 26°16'32"E; 1 May 2016; A. Vujić, J. Ačanski leg.; FSUNS 11243.

Turkey • 3 ♀♀; 12 km SW of Muğla; 37°07'40"N, 28°16'28"E; 660 m a.s.l.; 23 May 2011; M. Bartak, Kubik leg.; M. B. coll. 17921 to 17923 • 26 ♂♂; Muğla, University Campus; 37°09'42"N, 28°22'13"E; 700 m a.s.l.; 17-22 May 2011; M. Bartak, Kubik leg.; M. B. coll. 17927, 17928, 17930, 17931, 17937, 17938, 17940 to 17943, 17946, 17951, 17955 to 17960, 17965 to 17972 • 20 ♀♀; Muğla, University Campus; 37°09'42"N, 28°22'13"E; 700 m a.s.l.; 17-22 May 2011; M. Bartak, Kubik leg.; M. B. coll. 17929, 17932 to 17936, 17939, 17944, 17945, 17947 to 17950, 17952 to 17954, 17961 to 17964 • 1 ♀; Muğla, University campus; 37°09'42"N, 28°22'21"E; 700 m a.s.l.; Apr.-May 2014; O. Dursun leg.; M. B. coll. 10463 • 3 ♀♀; Muğla, 13 km NE pine wood; 37°14'50"N, 28°30'00"E; 1200 m a.s.l.; 23-27 Jun. 2015; M. Bartak, Kubik leg.; M. B. coll. 17924 to 17926 • 4 ♀♀; Bozdağ mountain, Near Bozdağ; 38°22'28"N, 28°04'38"E; 1140 m a.s.l.; 7 Jun. 2014; A. Vujić, J. Ačanski leg.; FSUNS 06945, 06946, 06948, 06951 • 2 ♂♂; Bozdağ mountain, Near Bozdağ; 38°22'28"N, 28°04'38"E; 1140 m a.s.l.; 7 Jun. 2014; A. Vujić, J. Ačanski leg.; FSUNS 06947, 06949.

Other material.

Greece, Lesvos • 1 ♀; Agiassos; 39°03'00"N, 26°22'60"E; 28 May 2010; Horsfield leg.; NMS • 1 ♀; Agiassos; 39°03'00"N, 26°22'60"E; 3 Jun. 2010; Wilkinson leg.; NMS [published in Ricarte et al. (2012), as Merodon serrulatus ] • 1 ♀; same data as for preceding; 8 Jun. 2010; NMS • 1 ♀; Agiassos; 39°03'00"N, 26°22'60"E; 1-8 Jun. 2010; Hancock leg.; GLAHM • 2 ♂♂; same data as for preceding; 28-29 May-Jun. 2010; GLAHM • 2 ♀; Agiassos; 39°03'36"N, 26°23'30"E; 1 Jun. 2010; Horsfield leg.; NMS [published in Ricarte et al. (2012), as Merodon serrulatus ] • 1 ♀; Agiassos; 39°03'36"N, 26°23'30"E; 28 May 2010; Horsfield leg.; NMS • 1 ♂; 3.5 km S Agiassos; 39°04'15"N 26°22'17"E; 860 m a.s.l.; 8 Jun. 2004; M. Kapsali leg.; MZH • 1 ♂; Agiassos; 39°04'17"N, 26°22'22"E; 1910 m a.s.l.; 26 May 2003; C. J. Palmer leg.; WML 298/03 • 1 ♀; same data as for preceding; WML 310/03 • 1 ♂; SW from Agiassos; 39°04'35"N, 26°22'03"E; 24 May 1988; NBCN • 1 ♀; Potamia river; 39°13'36"N, 26°06'48"E; 1-8 Jun. 2010; Hancock leg.; GLAHM • 1 ♂; 2 km S Gavathas; 39°16'11"N, 25°58'33"E; 5 May 2005; M. Hull leg.; WML • 1 ♂; 5.7 km NW Mantamados; 39°21'19"N, 26°17'52"E; 31 May 2004; E. Lamborn leg.; MZH.

Figures

Figure 4. Merodon serrulatus, lateral view. A, C metatrochanter, metafemur and metatibia B, D-F metaleg. A-B male (Spain) C female (Spain) D male (France) E male (Greece) F male (Russia). Scale bar: 2 mm.

Figure 7. Distribution map of Merodon serrulatus species group.

Figure 12. Antenna. A Merodon opacus sp. nov., outer side, lateral view, male B Merodon opacus sp. nov., inner side, lateral view, male C Merodon opacus sp. nov., dorsal view, male D Merodon opacus sp. nov., outer side, lateral view, female E Merodon opacus sp. nov., inner side, lateral view, female F Merodon opacus sp. nov., dorsal view, female G Merodon disjunctus sp. nov., outer side, lateral view, male H Merodon disjunctus sp. nov., inner side, lateral view, male I Merodon disjunctus sp. nov., outer side, lateral view, female J Merodon defectus sp. nov., outer side, lateral view, male K Merodon defectus sp. nov., outer side, lateral view, female. Scale bar: 1 mm.

Figure 13. Metaleg, lateral view. A Merodon opacus sp. nov., male B Merodon opacus sp. nov., female C Merodon hirsutus, male D Merodon hirsutus, female E Merodon defectus sp. nov., male. Scale bar: 2 mm.

Figure 14. Male genitalia. A Merodon defectus sp. nov., epandrium, lateral view B Merodon defectus sp. nov., epandrium, ventral view C Merodon serrulatus, epandrium, ventral view D Merodon defectus sp. nov., hypandrium, lateral view E Merodon hirsutus, epandrium, lateral view F Merodon hirsutus, epandrium, ventral view G Merodon hirsutus, hypandrium, lateral view, H Merodon opacus sp. nov., epandrium, lateral view I Merodon opacus sp. nov., epandrium, ventral view J Merodon opacus sp. nov., hypandrium, lateral view. Abbreviations: al-anterior surstyle lobe, bp-basolateral protrusion, c-cercus, l-lingula, pl-posterior surstyle lobe. Scale bar: 0.2 mm.

Figure 20. Head, dorsal view. A Merodon hirsutus, male B Merodon hirsutus, female C Merodon opacus sp. nov., male. Scale bar: 2 mm.

Figure 21. Abdomen. A Merodon opacus sp. nov., dorsal view, male B Merodon opacus sp. nov., dorsal view, female C Merodon opacus sp. nov., lateral view, male D Merodon opacus sp. nov., lateral view, female E Merodon hirsutus, lateral view, male F Merodon hirsutus, dorsal view, female G Merodon hirsutus, lateral view, female. Scale bar: 2 mm.

Figure 31. Light micrographs of Merodon opacus sp. nov. puparium. A puparium in dorsal view B cephalopharyngeal skeleton in lateral view. Abbreviations: C-cibarium, Cs-clypeal sclerite, Dc-dorsal cornu, Is-intermediate sclerite, M-mandibles, Mr-mortar, P-pestle, T-tentorium, Vc-ventral cornu. Scale bars: 3 mm (A); 500 μm (B).

Figure 32. SEM micrographs of Merodon opacus sp. nov. puparium. A posterior respiratory process in polar view showing the spiracular plate B anterior spiracle C pupal spiracle. Scale bars: 200 μm (A); 100 μm (B, C).

Figure 35. Different types of habitats of Merodon serrulatus species group. A Lesvos (Greece), habitat of Merodon opacus sp. nov., Photograph by Ante Vujic B Siberia, Teletskoye Lake (Russia), habitat of Merodon serrulatus, Photograph by Jeroen van Steenis C Morocco, habitat of Merodon sophron, Photograph by Ante Vujic D Tajikistan, habitat of Merodon nigrocapillatus sp. nov., Photograph by Anatolij Barkalov.