Melanostoma polynesiotes Mengual & Ramage 2018, sp. nov.
Creators: name: Ramage, Thibault
name: Charlat, Sylvain
name: Mengual, Ximo
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Melanostoma
Melanostoma polynesiotes

description: Melanostoma polynesiotes Mengual & Ramage sp. nov.
urn:lsid:zoobank.org:act: C80A600A-2ACE-4BBC-8B3F-D87A6878EA34
Figs 4A, C–D, 6 F–G, 9 D–F
Differential diagnosis
Species with face entirely black (Fig. 4C), scutum and scutellum black (Fig. 4A), and metasternum greatly reduced, with deep posterior incision on each side (typical metasternum for this genus). Easy to distinguish from other species in French Polynesia by its overall black coloration.
Etymology
The specific epithet polynesiotes refers to the country where this species occurs, French Polynesia, and it means ‘belonging to, pertaining to’ in Greek. The specific epithet is to be treated as a noun in apposition.
Material examined
Holotype FRENCH POLYNESIA: ♂, Tahiti Island, Tahiti Iti, Mount Te Atara Trail, 825 m a.s.l., 17°47′22.50″ S, 149°14′53.91″ W, genitalia in microvial, “FRENCH POLYNESIA: // Tahiti, Tahiti iti – sentier vers // le Mt Atara, 20.IX.2012, sweeping, // 17°47′22.50″ S, 149°14′53.91″ W // 825 m. Leg.: T. Ramage // PF_922”, “DNA voucher specimen // ZFMK Lab code // D269 // Bonn, Germany”, “ ZFMK-DIP // 00019707 ” [barcode] “ HOLOTYPE // Melanostoma // polynesiotes // Det. X. Mengual 2016 ” [red] (MNHN).
Paratypes FRENCH POLYNESIA: Society Islands: 1 ♀, Tahiti, Mount Marau, 17°36′08″ S, 149°33′42″ W, 970 m a.s.l., 31 Mar. 2007, Malaise trap, E. Clardige leg. (ZFMK: symbiocode_04430, ZFMK-DIP-00046220); 1 ♂, Tahiti, Mount Marau, 17°36′32.2″ S, 149°32′26.8″W, 1340 m a.s.l., 11 Jun. 2007, S. Charlat leg. (SCL: symbiocode_02320, completely destroyed during DNA extraction); 1 ♂, Tahiti, Tahiti Iti, Mount Te Atara Trail, 17°47′26.55″ S, 149°14′48.62″ W, 815 m a.s.l., 20 Sep. 2012, T. Ramage leg. (ZFMK: ZFMK-DIP-00019706); 1 ♂, Tahiti, Mont Marau, 1400 m a.s.l., 27 Aug. 2017, T. Ramage and F. Jacq leg. (ZFMK: ZFMK-DIP-00026902); 1 ♀, Tahiti, Papenoo Valley, Te Faaiti Natural Park, 17°35′34.96″ S, 149°26′32.37″ W, 296 m a.s.l., Malaise trap, 13 Mar. 2018, F. Jacq leg. (ZFMK: ZFMK-DIP-00040465).
Description
Male
LENGTH (N = 1). Body 9.4 mm; wing 7.0 mm.
HEAD (Fig. 4D). Face almost straight, with a small facial tubercle that seems medially divided, black, yellow pilose, white-silver pollinose; gena black, shiny; lunule dark, a bit paler than frons; frons shiny black, slightly pale pollinose basolaterally, pale pilose; vertical triangle black, black pilose; scape and pedicel brown, paler than basoflagellomere, black pilose; basoflagellomere black; arista brown basally, darkening apically, pubescent with pile shorter than arista width; eye bare, holoptic; occiput black, pale pollinose, yellow pilose on ventral ¾ and dark pilose on dorsal ¼.
THORAX (Figs 4A, C, 6F). Scutum black, mostly shiny, pale pollinose anteriorly until notopleuron, with erected, relatively long yellow pile; postalar callus a bit lighter, tawny; scutellum black with erected yellow pile, subscutellar fringe with yellow pile. Pleuron black, mostly pale pollinose, yellow pilose; metasternum bare, reduced, with deep anterior incision on each side; calypter yellow; plumula yellow; halter yellow; posterior spiracular fringes yellow.
WING. Hyaline, entirely microtrichose, except cell c basally bare.
LEGS. Coxae dark; metatrochanters pale; femora black with basal and apical apices yellow; pro- and mesotibia yellow with a medial dark annulus; pro- and mesotarsomeres yellow; metatibia dark with basal 1/5 yellow; metatarsomeres dark.
ABDOMEN. Parallel-sided, unmargined, entirely black. Terga 2–5 black pilose medially and yellow pilose laterally; sterna dark.
MALE GENITALIA. Enlarged (Fig. 4G); surstylus tapers to slender acute apex, curved towards dorsal part; superior lobes (postgonites) elongated, with rounded apex, with a spur-like process medially on the ventral margin and another spur-like process dorsally pointed anteriorly; hypandrium with two arms ending with two spur-like processes (one small and one larger); phallus one-segmented, distiphallus with two spur-like processes on each side, one pointed dorsally, the other pointed ventrally (Fig. 9 D–F).
Female
Similar to male except for normal sexual dimorphism and as follows: frons shiny black, with pale pollinosity along eye margin on ventral ½ between antennae and anterior ocellus; postalar callus black; sternum 2 dark on anterior ½ and pale on posterior ½.
Geographical distribution
Species only known from Tahiti (French Polynesia).
Status in French Polynesia
Endemic.
Flowers visited
No records.
Genetics
The GenBank accession numbers for this species are: 28S gene (MF446466, specimen ZFMK-DIP-00019707), 18S gene (MF446421, specimen ZFMK-DIP-00019707), protein-coding COI gene (MF446515, specimen ZFMK-DIP-00019707; MF446522, specimen ZFMK-DIP-00019706). The BOLD Process IDs for the DNA barcodes (5′–COI) for this species are: SYC2242-14 (= KX054855, specimen symbiocode_02320), and SYC4350-14 (= KX054856, specimen symbiocode_04430). The Barcode Index Number (BIN) for these specimens is BOLD:ACN3906 (https://doi.org/10.5883/BOLD:ACN3906).
References
Ramage et al. 2017 (as Syrphidae, unknown; symbiocode_02320 and symbiocode_04430).
Remarks
A singular species due to its coloration, found at relatively high altitudes on Tahiti (Society Islands). A male paratype (symbiocode_02320) was completely destroyed during the DNA extraction and only its DNA template remains in the Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, France.
Species of the genus Melanostoma Schiner, 1860 occur in all biogeographic regions except the Neotropics. This new species differs from the other species of Melanostoma in the Australasian and Oceanian Regions, namely M. univittatum (Wiedemann, 1824), M. apicale Bigot, 1884, M. fasciatum (Macquart, 1850) and M. fumivenosum Doesburg, 1966, by the dark body coloration, very small facial tubercle and distinct male genitalia (Burt & Mengual 2018). Below we provide a key to the species of Melanostoma in the Australasian and Oceanian Regions.
description: Published as part of Ramage, Thibault, Charlat, Sylvain & Mengual, Ximo, 2018, Flower flies (Diptera, Syrphidae) of French Polynesia, with the description of two new species, pp. 1-37 in European Journal of Taxonomy 448 on pages 15-18, DOI: 10.5852/ejt.2018.448, http://zenodo.org/record/3814059