Macrostomus xavieri, Rafael, José Albertino & Cumming, Jeffrey M., 2015

Rafael, José Albertino & Cumming, Jeffrey M., 2015, Revision of the genus Macrostomus Wiedemann (Diptera, Empididae, Empidinae). IV. The amazonensis species-group, Zootaxa 3947 (1), pp. 109-121 : 118-120

publication ID	https://doi.org/ 10.11646/zootaxa.3947.1.7
publication LSID	lsid:zoobank.org:pub:54A83A1C-7F6E-416C-88C3-E4D3916E1698
DOI	https://doi.org/10.5281/zenodo.6106258
persistent identifier	https://treatment.plazi.org/id/1755937A-FFE0-9A54-FF47-FF63A8908725
treatment provided by	Plazi
scientific name	Macrostomus xavieri
status	sp. nov.

Treatment

Macrostomus xavieri View in CoL sp. nov.

( Figs 45–53 View FIGURES 45 – 53 , 62–63 View FIGURES 54 – 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 View FIGURES 54 – 63 , paratype). Halter dark brown, partially white at knob. Abdomen shiny black. Terminalia with tergite 8 ( Fig. 45 View FIGURES 45 – 53 ) short, without sinus posteriorly and with shallow sinus anteriorly. Epandrium ( Fig. 46 View FIGURES 45 – 53 ) with anterodorsal and posterodorsal lobes short, almost same height. Anterior cercus wider ventrally ( Fig. 47 View FIGURES 45 – 53 ), with internal small process dorsally ( Fig. 49 View FIGURES 45 – 53 ); posterior cercus elongate longitudinally, curved inward. Cercal bridge ( Fig. 49 View FIGURES 45 – 53 ) small, projecting anteriorly from ventral margin of anterior cercus. Ventral projection of cercus widened, with setae placed on small protuberance ( Fig. 48 View FIGURES 45 – 53 ). Hypandrium ( Fig. 47 View FIGURES 45 – 53 ) 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 View FIGURES 54 – 63 ). Terminalia with tergite 8 and sternite 8 same length ( Fig. 50 View FIGURES 45 – 53 ). Tergite 8 ( Fig. 51 View FIGURES 45 – 53 ) with distal sinus. Sternite 8 ( Fig. 52 View FIGURES 45 – 53 ) with small distinct lateral sinus at basal third. Genital fork ( Fig. 53 View FIGURES 45 – 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 View FIGURES 45 – 53 ), and a genital fork with detached ( M. amazonensis and M. paraiba ) or nearly detached ( M. xavieri ) lateral arms ( Fig. 53 View FIGURES 45 – 53 ).