Revision of the genus Macrostomus Wiedemann (Diptera, Empididae, Empidinae). IV. The amazonensis species-group Author Rafael, José Albertino Author Cumming, Jeffrey M. text Zootaxa 2015 3947 1 109 121 journal article 10.11646/zootaxa.3947.1.7 157445af-8a6b-4ebd-8f19-7a1fd783268b 1175-5326 237979 54A83A1C-7F6E-416C-88C3-E4D3916E1698 Macrostomus albicaudatus sp. nov. ( Figs 10–17 , 56–57 ) Diagnosis . Thorax yellow. Abdomen black with male terminalia yellow and female terminalia white. Male tergite 8 short, without sinus anteriorly and with shallow sinus posteriorly. Epandrium with posterodorsal lobe of epandrium higher than anterodorsal lobe. Anterior cercus with thin process at posterior margin; posterior cercus vertically elongate with one small secondary protuberance. Hypandrium without setae and with sinus on posterior margin. Female hind tibia without pinnate setae. Description . Holotype male. Body length 2.8 mm; wing length 3.2 mm. Width of frons slightly narrower than anterior ocellus width. Antenna velvety black with pedicel rather yellow. Palpus yellow. Thorax shiny yellow. Thoracic setae: 3–4 dorsocentrals, 3–5 antepronotals, 1–3 proepisternals, 2 pairs of scutellars. Legs shiny yellow with apex of hind femur, apex of hind tibia and all tarsomeres 4–5 darker. Hind femur ( Fig. 10 ) with slender, longer ventral and dorsal setae near middle where femur (as seen in dorsal view) is slightly swollen; no anteroventral setae at distal third. Wing ( Fig. 56 , paratype ). Halter yellow, lighter distally. Abdomen shiny black with segment 1, base of segment 2 and terminalia yellow. Terminalia with tergite 8 short, without sinus anteriorly, with shallow sinus posteriorly ( Fig. 11 ). Epandrium with posterodorsal lobe higher than anterodorsal lobe ( Fig. 12 ). Anterior cercus with thin process at posterior margin; posterior cercus elongate vertically with one small secondary protuberance. Cercal bridge ( Fig. 13 ) small, flat, somewhat cordiform-shaped, connected anteriorly to anterior cercus. Ventral projection of cercus thin, with setae distally ( Fig. 12 ). Hypandrium ( Fig. 14 ) without setae, with moderately pronounced sinus on posterior margin. Female. Hind femur without slender anteroventral setae near middle. Hind tibia without pinnate setae. Wing ( Fig. 57 ). Terminalia white. Tergite 8 with distinct sulcus posteriorly and tergite 10 with sulcus anteriorly ( Fig. 15 ). Sternite 8 narrow anteriorly, distinctly expanded posteriorly with lateral projections rounded (as seen ventrally) and only slightly acuminate ( Fig. 16 ). Genital fork ( Fig. 17 ) small, without lateral arms. Genital chamber membranous with central sclerotized line. Geographical distribution . Brazil (Roraima, Amazonas, Pará). Type Material . HOLOTYPE ♂: “ BRAZIL , Amazonas, Manaus, F[azenda] Esteio, BR-174, km-41, ZF3”; “ 24–27.viii.1993 , F.F.Xavier”; “ Macrostomus albicaudatus Holótipo ♂” (red label) ( INPA ). PARATYPES . BRAZIL . Same data as holotype (1♀ INPA ); Amazonas, Manaus, PDBFF /WWF, Proj. Bert Klein, iii.1986 , Malaise, Res. 1208 ( 1♂ CNC ); viii.1984 ( 1♂ CNC ); Reserva Ducke, 24.v.1988 , J.A. Rafael & Socorro Rosa, flor de Miconia nervosa (1♀ INPA ); 15.vi.1988 (1♀ CNC ); 27.vii.1988 (1♀ INPA ); 13.iv.1989 ( 1♂ , 1♀, same pin, INPA ); 4.v.1989 ( 2♂ , 1♀ INPA ); 11.v.1989 ( 1♂ CNC ); 08.vi.1989 ( 2♂ , 2♀ INPA ); Parque Nac. Jau, Rio Jau, Ig. Patauá, 01º53'16''S 61º44'07''W , varredura, J.A. Rafael & J. Vidal ( 2♂ INPA ), Rio Jau, 11–30.x.1993 , J. Vidal ( 1♂ CNC ); Rio Unini, Democracia, 0 1 º 43'54''S 61 º 54'32''W , 20–24.vi.1996 , A.L. Henriques, J. Vidal & F.L. Oliveira, varredura ( 1♂ CNC ); Roraima, Pacaraima, 25.iv.–5.vii.1988 , Eq. J.A. Rafael, flor de Heliconia sp ( 1♂ , 2♀ CNC ); Serra Pacaraima, 27.viii.1987 , J.A. Rafael, Elias Bindá & A.L. Henriques, flor de Heliconia sp, ( 1♂ , 1♀ INPA ); Pacaraima, BR 174, 0 4 º 27'04''N 61 º 07'56''W , varredura, J.A. Rafael & J. Vidal ( 1♂ INPA ); Pará, Benevides, Faz. Morelândia, J.A.Rafael, arm. Malaise, 14.xi.1986 (1♀ INPA ); Rio Trombetas, Cruz Alta, 25–28.vii.1992 , arm. Malaise, J. Vidal (1♀ INPA ). Holotype condition . Pinned, in good condition, not dissected. Etymology . From Latin albus = white, caudatus = with tail, in reference to the white female terminalia. Variation . Some paratypes with abdomen dark yellow. Discussion . Macrostomus albicaudatus sp. nov. appears closely related to M. trombetensis sp. nov. based on a similar epandrium with the posterodorsal lobe higher than the anterodorsal lobe in the male ( Figs 12 , 39 ), anterior cercus with a thin process at posterior margin ( Figs 12 , 40 ), posterior cercus elongate with one small secondary protuberance ( Fig. 12 ), and female sternite 8 narrow anteriorly and distinctly expanded posteriorly ( Figs 16 , 43 ).