Microdon CR-99 Thompson, in litt. [see below under Molecular data] Microdon MRC 20 Thompson, in litt. [see below under Molecular data] Revision of the Neotropical species of the hoverfly genus Serichlamys Curran, 1925 (Diptera, Syrphidae, Microdontinae) Reemer, Menno Mengual, Ximo ZooKeys 2025 2025-06-24 1243 51 106 Reemer Reemer 2025 Insecta Syrphidae Serichlamys Animalia Diptera Arthropoda species chloraspis sp. nov.   Figs 5, 26, 31, 64–68, 139      MicrodonCR-99 Thompson, in litt. [see below under Molecular data]     MicrodonMRC 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. Skevingtonleg.;  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: “  Serichlamyssp.// Det. M. Reemer 2016// Voucher code MR 1175 ” [GenBank accession no.  PQ 628996].    Paratypes. Costa Rica• 1 ♂; Puntarenas, Osa Peninsula,  2.5 kmS Rincón;  8°42'1"N, 83°30'50"W;  50 masl;  10–11 Aug. 2001; S. A. Marshallleg.; 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. Brownleg.; coll.  UCRC[specimen code  UCRCENT 69104].   Additional specimens.   Costa Rica• 3 ♂; Higuito, San Mateo; Pablo Schildleg.;  USNM[  USNMspecimen 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 masl,  17 Sep. 2003, M. Moragaleg.; 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 maleBody 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 COIbarcode, 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. botiReemer, sp. nov.,  S. pallitarsisReemer & Mengual, sp. nov.and  S. varicaudataReemer & 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  Serichlamyswith 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).   Figures 64–68.   Serichlamys chloraspisReemer, sp. nov.male, holotype 64habitus, dorsal 65habitus, lateral 66head, frontal 67head, lateral 68head, 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 holotypemale was successfully sequenced and its DNA barcode clusters together ( BS= 100) with the COIsequence of one of the paratypes(  MZHS 264), which had previously been identified as ‘  MicrodonCR99-10 ’ in GenBank, and a public sequence of another  Serichlamysspecimen from Costa Rica, previously identified as  MicrodonMRC- 20. Both codes or name-holders are known to be used by F. C. Thompson and likely refer to the same species,  S. chloraspisReemer, 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. 5197434318 2010-07-30 CNC J. H. Skevington Costa Rica 1191 8.78578 Los Cruces 1 -82.95995 Label PQ 628996 1 1 holotype 5197434328 EU 431495 2001-08-10 2001-08-11 2001-08-10 DEBU, MZH S. A. Marshall Costa Rica 50 8.700277 Rincon 21 -83.513885 Osa Peninsula S 264 1 1 Puntarenas paratype 5197434391 1998-06 UCRC B. Brown Costa Rica 8.680556 Peninsula de Osa 21 -83.52556 UCRC ENT 69104 1 1 Puntarenas paratype 5197434336 USNM Pablo Schild Costa Rica San Mateo Higuito USNMENT 01866950, USNMENT 01866952 3 3 5197434389 2003-09-17 MNCR M. Moraga Costa Rica Area de conservacion Osa 200 8.455 Cerro Puma 77 -83.495 Golfito, Sector La Leona MNCR - A 3780889, INB 0003780889 1 1 Puntarenas