Macrostomus xavieri Rafael & Cumming, 2015, sp. nov.
Creators: name: Rafael, José Albertino
name: Cumming, Jeffrey M.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Empididae
Macrostomus
Macrostomus xavieri

description: Macrostomus xavieri sp. nov.
(Figs 45–53, 62–63)
Diagnosis. Thorax entirely black. Abdomen including terminalia black. Male tergite 8 short, with shallow sinus anteriorly. Posterior cercus curved inward. Female: fore coxa black, remaining yellow; female and some males with hind femur black and yellow banded. Hind tibia without pinnate setae.
Description. Holotype male. Body length 2.3 mm; wing length 2.3 mm. Width of frons approximately subequal to anterior ocellus width. Antenna velvety black. Palpus brown. Thorax shiny black. Thoracic setae: 3–4 dorsocentrals, 2–3 antepronotals, 1–3 proepisternals, 1–2 pairs of scutellars. Legs shiny yellow with apex of hind femur, almost entire hind tibia and all tarsomeres 3–5 black. Hind femur with 1 anteroventral seta slightly stronger at distal third. Wing (Fig. 62, paratype). Halter dark brown, partially white at knob. Abdomen shiny black. Terminalia with tergite 8 (Fig. 45) short, without sinus posteriorly and with shallow sinus anteriorly. Epandrium (Fig. 46) with anterodorsal and posterodorsal lobes short, almost same height. Anterior cercus wider ventrally (Fig. 47), with internal small process dorsally (Fig. 49); posterior cercus elongate longitudinally, curved inward. Cercal bridge (Fig. 49) small, projecting anteriorly from ventral margin of anterior cercus. Ventral projection of cercus widened, with setae placed on small protuberance (Fig. 48). Hypandrium (Fig. 47) with few uniseriated setae medially, without sinus on posterior margin.
Female. Fore coxa black; hind femur banded with yellow at base and subapically, black at middle and apically. Mid tibia with 1 slightly longer posterodorsal seta near middle. Hind tibia without pinnate setae. Wing (Fig. 63). Terminalia with tergite 8 and sternite 8 same length (Fig. 50). Tergite 8 (Fig. 51) with distal sinus. Sternite 8 (Fig. 52) with small distinct lateral sinus at basal third. Genital fork (Fig. 53) small, with elongate lateral arms. Genital chamber membranous.
Geographical distribution. Guyana, Brazil (Amazonas).
Type material. HOLOTYPE ♂: “ BRASIL, Amazonas, Manaus, F[azenda] Esteio, BR-174, km-41, ZF3”, “ 21–23.x.1993, F.F.Xavier” “ Macrostomus xavieri Holótipo ♂” (red label) (INPA). PARATYPES. BRAZIL. Same data as holotype, except 17-21.i.1994 (3♂, 2♀ INPA; 3♂, 2♀ CNC). GUYANA, Coll. Richards & Smart, B.M. 1937–776, Kaieteur, high forest, 05.ix.1937 (2♂, 1♀ BMNH).
Holotype condition. Pinned, in good condition, not dissected.
Etymology. Named in honor of Mr. Francisco Felipe Xavier Filho, an INPA technician who has collected many insects in the Amazon Basin.
Variation. Some male specimens have hind femur banded with yellow at base and subapically, and black at middle and apically.
Discussion. Macrostomus xavieri sp. nov. may be related to both M. amazonensis sp. n. and M. paraiba sp. nov. Females of all three species have similar terminalia with sternite 8 bearing a lateral cleft that is smaller and more basal in M. xavieri (Fig. 50), and a genital fork with detached (M. amazonensis and M. paraiba) or nearly detached (M. xavieri) lateral arms (Fig. 53).
description: Published as part of Rafael, José Albertino & Cumming, Jeffrey M., 2015, Revision of the genus Macrostomus Wiedemann (Diptera, Empididae, Empidinae). IV. The amazonensis species-group, pp. 109-121 in Zootaxa 3947 (1) on pages 118-120, DOI: 10.11646/zootaxa.3947.1.7, http://zenodo.org/record/237979