Serichlamys varicaudata Reemer & Mengual, 2025

Reemer, Menno & Mengual, Ximo, 2025, Revision of the Neotropical species of the hoverfly genus Serichlamys Curran, 1925 (Diptera, Syrphidae, Microdontinae), ZooKeys 1243, pp. 51-106 : 51-106

Serichlamys varicaudata Reemer & Mengual sp. nov.

Figs 1–4 , 11 , 17 , 27 , 29 , 33 , 35 , 118–125 , 141

Serichlamys sp. ECU 1: Wong et al. 2023: supplementary data files 1, 2, 4, 5, 7.

Type material.

Holotype. Ecuador • 1 ♂, holotype of Serichlamys varicaudata sp. nov.; Napo Prov., Yanayacu Biological station , trail up to; 0.592368°S, 77.890993°W, 2200 m asl; 18 Aug. 2022; X. Mengual leg.; INABIO. Label 1: “ ECUADOR: Napo Prov., Yanayacu // Biological Station, trail up to // 0 .592368°S 77.890993°W, // 2200 m., 18 Aug. 2022, hand-net // Leg.: X. Mengual ”; label 2 [barcode label]: “ ZFMK -DIP-00095371 ” . Paratypes. Ecuador • 1 ♀; Zamora Chinchipe, San Francisco, Reserva Biológica S. Francisco, trail Atajo ; 03°58'30"S, 79°04'25"W; 2000 m asl; 25 Feb. – 3 Mar. 2009; M. Pollet & A. De Braekeleer leg.; yellow pan trap; RBINS • 3 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF, T 2 to Camino Canal ; 8 Aug. 2012; X. Mengual leg.; 2 in ZFMK [ ZFMK -DIP-00107320 , ZFMK -DIP-00107321 ], 1 in INABIO [ ZFMK DIP 00107323 ] • 1 ♂ 1 ♀; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF; 26 Jul. 2012; X. Mengual leg.; ZFMK [ ZFMK -DIP-00107324 , ZFMK -DIP-00107325 ] • 1 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 31 Jul. 2012; X. Mengual leg.; ZFMK [ ZFMK -DIP-00107326 ] • 1 ♂, Napo Prov., Yanayacu Biological Station , grassland near station; 0.598355°S, 77.891378°W; 2150 m asl; 18 Aug. 2022; X. Mengual leg.; ZFMK [ ZFMK -DIP-00095358 ]; GenBank accession no. PQ 629013 • 1 ♂, Napo Prov., Yanayacu Biological Station , grassland near station; 0.598355°S, 77.891378°W; 2150 m asl; 21 Aug. 2022; X. Mengual leg.; ZFMK [ ZFMK -DIP-00095500 ]; GenBank accession no. PQ 628993 • 2 ♂, Napo Prov., Yanayacu Biological Station , grassland near station; 0.598355°S, 77.891378°W; 2150 m asl; 22 Aug. 2022; X. Mengual leg.; ZFMK [ ZFMK -DIP-00095541 ] and RMNH [ ZFMK -DIP-00095542 ]; GenBank accession no. PQ 629004 , PQ 629002 .

Additional specimens.

Ecuador • 1 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco , ECSF; 26–31 Jul. 2012; X. Mengual leg.; CNC [M. Reemer specimen code MR 0425, ZFMK -DIP-00107327 ]; GenBank accession no. PQ 628994 • 3 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 8 Aug. 2012; X. Mengual leg.; CNC [J. Skevington mol. spec. # 5471, ZFMK -DIP-00107329 ; J. Skevington specimen 30567, GenBank accession no. PQ 628997 ; J. Skevington specimen 30592, GenBank accession no. PQ 628999 ] • 2 sex unknown; same metadata as previous [J. Skevington specimen 30594, GenBank accession no. PQ 628998 ; GenBank accession no. OR 183415 ] • 4 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 31 Jul. – 11 Aug. 2012; 03°58'29"S, 79°04'42"W; 1890 m asl; X. Mengual leg.; ZFMK [ ZFMK -DIP-00068712 , 00068713, 00068716, 00068717]; GenBank accession no. PQ 629005 , PQ 629009 , PQ 629020 , PQ 629017 • 1 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 31 Jul. – 11 Aug. 2012; 03°58'29"S, 79°04'42"W; 1890 m asl; X. Mengual leg.; ZFMK [ ZFMK -DIP-00013508 ] ; • 2 ♀; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 31 Jul. – 11 Aug. 2012; 03°58'29"S, 79°04'42"W; 1890 m asl; X. Mengual leg.; RMNH [ ZFMK -DIP-00068714 ] and ZFMK [ ZFMK -DIP-00068715 ]; GenBank accession no. PQ 628995 , PQ 629001 • 1 ♂; Zamora-Chinchipe Prov., Cantón Zamora, Sector San Francisco, ECSF ; 8 Aug. 2012; X. Mengual leg.; ZFMK [ ZFMK -DIP-00068711 ]; GenBank accession no. PQ 629011 • 1 ♂; Napo Prov., Yanayacu Biological Station ; 00°35'44.3"S, 77°53'38.6"W; 2234 m asl; 29 Aug. - 3 Sep. 2019; X. Mengual leg.; ZFMK [ ZFMK -DIP-00068683 ]; GenBank accession no. PQ 629000 • 1 ♂; Napo Prov., Yanayacu Biological Station , trail up to; 0.592368°S, 77.890993°W; 2200 m asl; 18 Aug. 2022; X. Mengual leg.; ZFMK [ ZFMK -DIP-00095695 ] • 5 ♂; Napo Prov., Yanayacu Biological Station , environs; 0.5991°S, 77.891495°W; 2140 m asl; 14 Sep. 2023; X. Mengual leg.; INABIO [ ZFMK -DIP-00103503 ] and ZFMK [ ZFMK -DIP-00103504 , ZFMK -DIP-00103505 , ZFMK -DIP-00103507 , ZFMK -DIP-00103508 ] • 2 ♂; Napo Prov., Yanayacu Biological Station, stream trail ; 0.59952°S, 77.89434°W; 2180 m asl; 17 Sep. 2023; X. Mengual leg.; ZFMK [ ZFMK -DIP-00103600 , ZFMK -DIP-00103607 ] • 1 ♂; Napo Prov., Yanayacu Biological Station , forest edge; 0.5991°S, 77.891495°W; 2140 m asl; 14 Sep. - 19 Sep. 2023; X. Mengual leg.; Malaise trap; ZFMK [ ZFMK -DIP-00104346 ] .

Description

(based on holotype). Adult male Body size: 9.5 mm.

Head. Face occupying ~ 2 / 5 of head width in frontal view; shiny black; white setulose, except black setulose on dorsal 1 / 4. Gena very narrow; black; white setulose. Oral margin laterally not produced. Frons black; medially bare, laterally black setulose except white setulose along eye margin. Vertex black; black setulose. Occiput black; dorsal 1 / 2 golden yellow setulose, ventral 1 / 2 white setulose. Eye bare. Antenna: scape black, pedicel and postpedicel dark brown; antennal ratio ~ 4: 1: 5.

Thorax. Scutum shiny black with bronze sheen; golden yellow setulose. Postpronotum and postalar callus shiny brown; golden yellow setulose. Scutellum trapezoid, of same colour as scutum, with two apical calcars as long as ~ 2 / 5 of scutellar length. Pleura greyish brown, except meron and ventral parts of katepisternum blackish. Anepisternum with shallow sulcus; golden yellow setulose anterodorsally and posterodorsally, widely bare medially and ventrally. Anepimeron golden yellow setulose. Katepisternum with patch of white setulae dorsally and a few white setulae ventrally. Katatergite long microtrichose, anatergite short microtrichose. Calypter and halter pale yellow.

Wing: hyaline; microtrichose, except bare on basal 1 / 4 of cell r 1, most of cell br (only microtrichose along vena spuria), posterobasal 1 / 2 of cell bm, anterobasal 1 / 3 of cell cup, and basomedian 3 / 5 of alula.

Legs: femora black; yellow to white setulose. Tibiae black, apices narrowly brown; white setulose. Tarsi black with apical tarsomere yellowish brown; black setulose dorsally, yellow setulose ventrally. Coxae and trochanters blackish; yellow and white setulose.

Abdomen. Tergites blackish, with lateral and posterior margins brown. Tergite 1 yellowish white setulose. Tergite 2 shiny with three large dull maculae; yellowish white setulose. Tergite 3 dull on most of surface, with lateral and posterior margins shiny; yellowish white setulose on shiny parts, black setulose on dull parts. Tergite 4 semi-shiny; reddish yellow setulose laterally and posteriorly, black setulose anteriorly and medially, white setulose in anterolateral corners. Sternites blackish; yellow setulose. Genitalia as in Fig. 141 .

Female. As male, except for following differences. Face, frons, and vertex black setulose except for pair of small patches of white setulae along eye margin. Scutum, scutellum, and pleura black setulose. Tergite 5 yellow to yellowish brown; yellow setulose.

Diagnosis.

Body length: male 9–10 mm (n = 10), female 11–12 mm (n = 2). Superficially, this species looks most similar to S. boti Reemer , sp. nov., S. chloraspis Reemer , sp. nov., and S. pallitarsis Reemer & Mengual , sp. nov., which are of similar size and colouration. These four species all have a black face, entirely dark tibiae, a uniformly coloured postpedicel, and a large rectangular dull area on tergite 3. The combination of the following characters distinguishes S. varicaudata Reemer & Mengual , sp. nov. from the other three species: wing cell dm entirely microtrichose (partly bare in S. boti Reemer , sp. nov.), scutum and scutellum without strong metallic green shine (green metallic in S. chloraspis Reemer , sp. nov.), tergite 2 with lateral dull parts large (Fig. 33 ) (small in S. boti Reemer , sp. nov. and S. pallitarsis Reemer & Mengual , sp. nov.; Figs 30 , 32 ), hind metatarsus dorsally black (orange in S. boti Reemer , sp. nov. and S. pallitarsis Reemer & Mengual , sp. nov.). Male genitalia as in Fig. 141 .

Notes.

In the studied male specimens, the degree to which tergite 4 is covered with red setulae varies from only the apical 1 / 3 to the entire tergite (Figs 123–125 ). The colour of the setulae on the vertex also varies from entirely golden yellow to entirely black.

Etymology.

The specific epithet is composed of the Latin words varius (different) and cauda (tail). The name refers to the variability of the colouration of both integument and setulosity of tergite 4.

Molecular data.

Several DNA barcodes were successfully obtained from multiple specimens from Ecuador and they were recovered in a well-supported cluster (BS = 98.8) in the NJ tree. The intraspecific similarity ranges from 99.111 to 100 %.

Distribution.

This species is only known from Ecuador, where it was found on eastern and western slopes of the Andes at elevations between 1800 and 2200 meters.

Figures

Figures 1–4. 1 wing of Serichlamys varicaudata Reemer & Mengual, sp. nov. Note posterior appendix on vein R 4 + 5 and near-rectangular (slightly acute) postero-apical corner pf cell r 4 + 5 2–4 anterior pleura of Serichlamys varicaudata Reemer & Mengual, sp. nov., lateral view 2 overview 3 proepisternum, note presence of setulae on the posterior part of this sclerite 4 anepisternum; note large bare medioventral part.

Figures 5–12. 5, 6 colour of face of Serichlamys species 5 black (S. chloraspis Reemer, sp. nov. male, holotype) 6 yellowish brown (S. serpentiphallus Reemer, sp. nov. male, holotype) 7–9 hind tibiae of Serichlamys species 7 with contrasting colour pattern (S. vexilliphallus Reemer & Mengual, sp. nov. male, holotype) 8 uniformly yellowish brown (S. mitis (Curran, 1940) male, specimen MR 1576) 9 dark (S. pallitarsis Reemer & Mengual, sp. nov. male, holotype) 10–12 antenna of Serichlamys species 10 postpedicel pale brown with apical 1 / 3 dark (S. mitis (Curran, 1940) male, specimen MR 1576) 11 postpedicel entirely dark brown (S. varicaudata Reemer & Mengual, sp. nov. male, holotype) 12 postpedicel entirely orange (S. pallitarsis Reemer & Mengual, sp. nov. female, paratype).

Figures 13–17. Tergite 3 of Serichlamys species. White lines in lower half of figures indicate position of dull maculae 13 S. melamitis Reemer, sp. nov. male, holotype 14 S. mellimitis Reemer, sp. nov. male, holotype 15 S. mitis (Curran, 1940) male, specimen MR 1576 16 S. mitis (Curran, 1940) female, specimen MR 1581 17 S. varicaudata Reemer & Mengual, sp. nov. male, holotype.

Figures 24–29. 24, 25. Microtrichiae on wing cell dm in Serichlamys species 24 S. boti Reemer, sp. nov. male, holotype 25 S. varicaudata Reemer & Mengual, sp. nov. male, holotype 26, 27 scutum and scutellum of Serichlamys males 26 S. chloraspis Reemer, sp. nov. holotype 27 S. varicaudata Reemer & Mengual, sp. nov. holotype 28, 29 hind tarsus of Serichlamys males 28 S. pallitarsis Reemer & Mengual, sp. nov. holotype 29 S. varicaudata Reemer & Mengual, sp. nov. holotype.

Figures 30–35. 30–33 tergite 2 of Serichlamys males. White lines in lower half of figures indicate position of dull maculae 30 S. boti Reemer, sp. nov. holotype 31 S. chloraspis Reemer, sp. nov. holotype 32 S. pallitarsis Reemer & Mengual, sp. nov. holotype 33 S. varicaudata Reemer & Mengual, sp. nov. holotype 34, 35 antenna of Serichlamys females 34 S. pallitarsis Reemer & Mengual, sp. nov. paratype 35 S. varicaudata Reemer & Mengual, sp. nov. paratype.

Figures 118–125. 118–121 Serichlamys varicaudata Reemer & Mengual, sp. nov. male, holotype 118 habitus, dorsal 119 habitus, lateral 120 head, frontal 121 head, lateral 122 Serichlamys varicaudata Reemer & Mengual, sp. nov. female, paratype: habitus, dorsal 123–125 Serichlamys varicaudata Reemer & Mengual, sp. nov. male: variation in colouration of setulosity of tergite 4.

Figures 138–141. Serichlamys male genitalia 138 S. boti Reemer, sp. nov. holotype 139 S. chloraspis Reemer, sp. nov. paratype 140 S. pallitarsis Reemer & Mengual, sp. nov. paratype, coll. USNM, specimen code MR 1595 141 S. varicaudata Reemer & Mengual, sp. nov., coll. ZFMK, specimen code MR 425.