Serichlamys serpentiphallus Reemer, 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 serpentiphallus Reemer sp. nov.

Figs 6 , 42 , 48 , 53–55 , 98–102 , 148

Type material.

Holotype. Brazil • 1 ♂, holotype of Serichlamys serpentiphallus sp. nov.; Nova Teutonia ; 27°11'S, 52°23'W; Oct. 1968; 300–500 m asl; F. Plaumann leg; RMNH. Label 1: “ Brasilien // Nova Teutonia // 27 ° 11 B, 52 ° 23 L // Fritz Plaumann // X. 1968 // 300–500 m ”; label 2: “ Museum Leiden // Collectie // Van Doesburg // rec. 1973 ”; label 3: “ Microdon // mus Curr. // det. v. Doesburg ”; label 4: “ Serichlamys sp. // Det. M. Reemer 2022 // Specimen code MR 1486 ”; label 5 (red): “ HOLOTYPE // Serichlamys // serpentiphallus // M. Reemer ” . Paratypes. Brazil • 6 ♂ with same data as holotype; RMNH • 1 ♂ with same data as holotype except date Oct. 1967; RMNH • 1 ♂ with same label data as holotype except date Nov. 1971; USNM [ USNMENT 01866947 • 1 ♂; Itatiaya, Est. Biologica ; 24 Oct. 1932; 1100 m asl; E. de Rio leg.; MZUSP.

Additional specimens.

Brazil • 1 ♂; Nova Teutonia ; 27 ° 11 ’ B, 52 ° 23 ’ L; 300–500 m asl; Nov. 1964; RMNH [M. Reemer specimen code: MR 0381 ] • 1 ♂; São Paulo, São Luis do Paraitinga, PESM, Núcleo Sta. Virginia ; 23.324194°S, 45.094000°W; 20 Nov. 2011; N. W. Perioto leg.; CNC [ CNC specimen code: CNC 1059094 ] • 1 ♀; São Paulo, São Luis do Paraitinga, PESM, Núcleo Sta. Virginia ; 23.324194°S, 45.094000°W; 20 Nov. 2011; N. W. Perioto leg.; CNC [ CNC specimen code: CNC 1059095 ]; GenBank accession no. PQ 629021 .

Description

(based on holotype). Adult male Body size: 8 mm.

Head. Face occupying ~ 1 / 3 of head width in frontal view; shiny yellowish brown (in Fig. 100 there appears to be a yellow median vitta, but this is an artefact of lighting conditions, which highlight some pale subcuticular structure); yellowish white setulose. Gena yellow; white setulose. Oral margin laterally hardly produced. Frons brown; medially bare, laterally black setulose. Vertex brown; golden yellow setulose. Occiput brown; dorsal 1 / 2 golden yellow setulose, ventral 1 / 2 white setulose. Eye bare. Antenna orange-brown; antennal ratio ~ 2: 1: 3.

Thorax. Scutum blackish brown with bronze sheen, margins brown; golden yellow setulose. Postpronotum and postalar callus brown; golden yellow setulose. Scutellum trapezoid, brown; golden yellow setulose; with two dorsoventrally flattened, spoon-shaped calcars as long as ~ 1 / 3 of scutellar length. Pleura brown. 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 narrow strip along vein RS in cell r 1, most of cell br (only microtrichose along vena spuria), posterobasal 1 / 5 of cell bm, anterobasal 1 / 4 of cell cup, and basomedian 2 / 3 of alula.

Legs: pale brown, with femora and hind metatarsus somewhat darker; yellow to white setulose, except mid and hind tarsus dorsally with some black setulae. Coxae and trochanters brown; yellow to white setulose.

Abdomen. Tergites dark brown, except lateral margins and posterior margin of tergite 4 paler brown. Tergite 1 white setulose. Tergite 2 medially shiny except for small median patch of grey microtrichia, laterally dull due to grey microtrichia; medially white setulose, laterally yellow setulose. Tergite 3 dull on most of surface, with lateral and posterior margins shiny; black setulose on dull parts, yellowish white setulose on shiny parts. Tergite 4 semi-shiny; golden yellow setulose laterally and posteriorly, black setulose anteriorly and medially. Sternites yellowish brown; yellowish white setulose. Genitalia as in Fig. 148 .

Female. One female probably belonging to this species was collected at the same site and date as one of the males listed among the additional specimens. It differs in paler overall colouration, which is probably either a result of the specimen being teneral at time of collecting, or of preservation methods. Tergites 4 and 5 are entirely yellowish brown.

Diagnosis.

Body length: male 7.5–8.5 mm (n = 10), female 8.5 mm (n = 1). Together with S. simpliciphallus Reemer , sp. nov. and S. spathulata Reemer , sp. nov., this species belongs to a group of three species of which most (not all!) specimens have dorsoventrally flattened, spoon-shaped calcars on the scutellum (Figs 51–57 ). From S. spathulata Reemer , sp. nov. it differs by the presence of separate patches of microtrichia on tergite 2 (Fig. 48 ), the brown postpedicel, and the structure of the male genitalia (Fig. 148 ). From S. simpliciphallus Reemer , sp. nov. this species can only be reliably distinguished by the structure of the male genitalia, most notably the shape of the phallus: S-shaped in S. serpentiphallus Reemer , sp. nov., straight in S. simpliciphallus Reemer , sp. nov. Other characters, such as colouration of integument and setulosity, as well as distribution of microtrichia on the tergites, were found to be too variable among the studied specimens. Females are undistinguishable from S. simpliciphallus Reemer , sp. nov. at present.

Etymology.

The name serpentiphallus is a noun composed of the Latin words serpens (snake) and phallus (phallus). It refers to the s-shaped phallus of the male of this species.

Molecular data.

The female from São Luis do Paraitinga ( CNC 1059095) was successfully sequenced. The identification of this specimen was based on the fact that it was collected at the same locality and date as CNC 1059094, a male which was identified based on its genitalia. The DNA barcode is placed with high support (BS = 99.6) together with a cluster that includes the sequences of S. spathulata Reemer , sp. nov. and Serichlamys sp. ( CNC 1059093; GenBank accession no. PQ 629019), although they differ considerably (similarity = 87.459 –87.541 %)

Distribution.

This species is known from the Brazilian States of São Paulo and Rio de Janeiro.

Figures

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 36–43. 36, 37 abdomen of Serichlamys males 36 S. trigonoides Reemer, sp. nov. holotype 37 S. mus (Curran, 1936) specimen USNMENT 01866933 (= MR 1587) 38, 39 hind leg of Serichlamys males 38 S. xanthocnemia Reemer, sp. nov. holotype 39 S. simpliciphallus Reemer, sp. nov. holotype 40–43 antenna of Serichlamys males (note that shape of postpedicel may vary within species, with apex acute or rounded) 40 S. mus (Curran, 1936) specimen MR 1587 41 S. spathulata Reemer, sp. nov. holotype 42 S. serpentiphallus Reemer, sp. nov. holotype 43 S. simpliciphallus Reemer, sp. nov. holotype.

Figures 44–49. Tergite 2 of Serichlamys, posterodorsal view. White lines in lower half of figures indicate position of patches of grey microtrichia (vary with viewing angle and lighting to get good view on shiny and dull parts) 44 S. mus (Curran, 1936) male, specimen MR 1587 45 S. mus (Curran, 1936) female, specimen MR 1606 46 S. spathulata Reemer, sp. nov. male, holotype 47 S. spathulata Reemer, sp. nov. female, paratype 48 S. serpentiphallus Reemer, sp. nov. male, holotype 49 S. simpliciphallus Reemer, sp. nov. male, holotype.

Figures 50–57. Scutellar calcars of Serichlamys 50 S. mus (Curran, 1936) male, holotype 51 S. spathulata Reemer, sp. nov. holotype, male 52 S. spathulata Reemer, sp. nov. female, paratype 53 S. serpentiphallus Reemer, sp. nov. male, holotype 54 S. serpentiphallus Reemer, sp. nov. male, paratype 55 S. serpentiphallus Reemer, sp. nov. male, paratype 56 S. simpliciphallus Reemer, sp. nov. male, holotype 57 S. simpliciphallus Reemer, sp. nov. male, paratype 1957 MZUSP.

Figures 98–102. Serichlamys serpentiphallus Reemer, sp. nov. male, holotype 98 habitus, dorsal 99 habitus, lateral 100 head, frontal 101 head, lateral 102 head, dorsal.

Figures 146–149. Serichlamys male genitalia (phallus grey-shaded) 146 S. mus (Curran, 1936) coll. USNM, USNMENT 01866933 147 S. spathulata Reemer, sp. nov. coll. JTS, specimen code MR 598 148 S. serpentiphallus Reemer, sp. nov. coll. RMNH, specimen code MR 381 149 S. simpliciphallus Reemer, sp. nov. holotype.