Revision of the Neotropical species of the hoverfly genus Serichlamys Curran, 1925 (Diptera, Syrphidae, Microdontinae) Author Reemer, Menno Naturalis Biodiversity Center, P. O. Box 9517, 2300 RA Leiden, Netherlands Author Mengual, Ximo 0000-0002-6185-9404 Museum Koenig Bonn, Leibniz-Institut zur Analyse des Biodiversitätswandels, Adenauerallee 127, 53113 Bonn, Germany & Instituto Nacional de Biodiversidad, División de Entomología, Quito, Ecuador text ZooKeys 2025 2025-06-24 1243 51 106 journal article 310605 10.3897/zookeys.1243.132809 28c57d26-3325-4685-88d9-7147a932a45f 494DA692-E7B5-455B-82B0-390DE5924743 Serichlamys chloraspis Reemer sp. nov. Figs 5 , 26 , 31 , 64–68 , 139 Microdon CR-99 Thompson, in litt. [see below under Molecular data] Microdon MRC 20 Thompson, in litt. [see below under Molecular data] Type material. Holotype . Costa Rica • 1 ♂ , holotype of Serichlamys chloraspis sp. nov. ; Los Cruces ; 8.78578°N , 82.95995°W ; 30 Jul. 2010 ; J. H. Skevington leg.; CNC . Label 1: “ COSTA RICA: Los Cruces // 30. vii. 2010 ; 1191 m . // 8.78578°N, 82.95995°W // J. H. Skevington ”; label 2: “ J. Skevington // Specimen # // 22180 ”; label 3 (green): “ Barcode of Life // DNA voucher specimen // Sample ID: JSS 22180 // BOLD Proc. ID: CNCDB 3735-11 ”; label 4: “ Serichlamys sp. // Det. M. Reemer 2016 // Voucher code MR 1175 ” [GenBank accession no. PQ 628996 ] . Paratypes . Costa Rica • 1 ♂ ; Puntarenas , Osa Peninsula , 2.5 km S Rincón ; 8°42'1"N , 83°30'50"W ; 50 m asl ; 10–11 Aug. 2001 ; S. A. Marshall leg.; coll. DEBU ; DNA voucher code MZH : S 264 ; specimen code M. Reemer MR 186; GenBank accession no. EU 431495 • 1 ♂ ; Puntarenas , Peninsula de Osa ; 8°40'50"N , 83°31'32"W ; June 1998 ; B. Brown leg.; coll. UCRC [specimen code UCRC ENT 69104 ] . Additional specimens. Costa Rica • 3 ♂ ; Higuito , San Mateo ; Pablo Schild leg.; USNM [ USNM specimen barcodes: USNMENT 01866950 , USNMENT 01866950 , USNMENT 01866952 ] • 1 ♀ ; Puntarenas , Area de conservacion Osa , Golfito, Sector La Leona , Cerro Puma , 8.455°N , 83.495°W , 200 m asl , 17 Sep. 2003 , M. Moraga leg.; specimen code MNCR - A 3780889 (= INB 0003780889 ); BOLD Process ID ASIND 083-12 ; GenBank accession no. PQ 629016 ; coll. MNCR . Description (based on holotype ). Adult male Body size: 10 mm . Head . Face occupying slightly less than 1 / 3 of head width in frontal view; shiny black; white setulose, except narrow bare patch below antennae. Gena very narrow; black; white setulose. Oral margin laterally not produced. Frons black; medially bare, laterally black setulose. Vertex black; black setulose except for small patch of golden yellow setulae anteriorly and a few scattered golden yellow setulae posteriorly. Occiput black; dorsal 1 / 3 golden yellow setulose, otherwise white setulose. Eye bare. Antenna blackish brown; antennal ratio ~ 4: 1: 5. Thorax . Scutum shiny black with clear green sheen; golden yellow setulose, except for small median patch of black setulae on anterior 1 / 3 and some scattered black setulae laterally posteriad of transverse suture. Postpronotum of same colour as scutum; golden yellow setulose. Postalar callus brown; yellow setulose with a few black setulae ventrolaterally. Scutellum trapezoid, with two calcars as long as ~ 1 / 4 of scutellar length; of same colour as scutum except calcars dull black; golden yellow setulose with a few black setulae posteriorly. Pleura shiny blackish brown. Anepisternum with shallow sulcus; golden yellow setulose anterodorsally, black setulose posterodorsally, widely bare medially and ventrally. Anepimeron golden yellow setulose with a few black setulae dorsally. Katepisternum with patch of pale yellow setulae dorsally and small patch of whitish setulae ventrally. Katatergite long microtrichose, anatergite short microtrichose. Calypter and halter pale yellow. Wing: hyaline; microtrichose, except bare on basal 1 / 8 of cell r 1 (along vein RS), most of cell br (only microtrichose along vena spuria), posterobasal 1 / 3 of cell bm, anterobasal 1 / 3 of cell cup, and basomedian 1 / 2 of alula. Legs: femora and tibiae black, with tibiae a little brownish at both ends; tarsi brown, with apical tarsomeres paler than basal four tarsomeres. Femora black setulose, with ventrobasal patches of pale setulae. Tibiae black setulose anteriorly, white setulose posteriorly. Coxae and trochanters blackish brown; white setulose. Abdomen . Tergites black. Tergite 1 yellow setulose, except black setulose near lateral margin. Tergite 2 golden yellow setulose, except for two large, bare, strongly metallic green shiny maculae, and black setulose along posterior half of lateral margin. Tergite 3 on most of surface with a mixture of short erect golden yellow and black setula; golden yellow setulae along posterior and lateral margins longer and more appressed, resulting in a fascia along these margins. Tergite 4 mostly short appressed black setulose, but longer pale yellow to whitish setulose along lateral margins and on pair of large posterior patches. Sternites blackish brown; sternite 1 bare; sternites 2 and 3 yellowish white setulose; sternite 4 black setulose. Genitalia as in Fig. 139 . Female. Unknown. The female listed under Additional material is included based on its COI barcode, but the specimen itself was not studied, as it was not possible for us to arrange a loan within the time frame of this study. Diagnosis. Body length: male 8–10 mm ( n = 6). Superficially, this species looks most similar to S. boti Reemer , sp. nov. , S. pallitarsis Reemer & Mengual , sp. nov. and S. varicaudata Reemer & Mengual , sp. nov. , which are of similar size and colouration. These species also share the following combination of characters: face black, tibiae entirely brown, tergite 3 broadly dull with narrow shiny margins (Fig. 64 ). However, this is the only known species of Serichlamys with a strong metallic green shine on scutum and scutellum (Figs 31 , 64 ). A weak metallic, sometimes green, shine also occurs in other species, but not as strong. In addition, there is a pair of large, smooth, metallic green maculae on tergite 2 (Fig. 31 ) (these maculae are not green in the three species mentioned above). Serichlamys chloraspis Reemer , sp. nov. male, holotype 64 habitus, dorsal 65 habitus, lateral 66 head, frontal 67 head, lateral 68 head, dorsal. Etymology. The specific epithet is composed of the Greek words chloros (green) and aspis (shield). This name refers to the metallic green scutum and scutellum of this species. Molecular data. The holotype male was successfully sequenced and its DNA barcode clusters together ( BS = 100) with the COI sequence of one of the paratypes ( MZH S 264), which had previously been identified as ‘ Microdon CR 99-10 ’ in GenBank, and a public sequence of another Serichlamys specimen from Costa Rica , previously identified as Microdon MRC- 20. Both codes or name-holders are known to be used by F. C. Thompson and likely refer to the same species, S. chloraspis Reemer , sp. nov. Distribution. This species is only known from Costa Rica , where it was found in the centre and southeast of the country at elevations between 50 and 1200 meters.