Revision of the genus Macrostomus Wiedemann (Diptera: Empididae: Empidinae). I. The ferrugineus species-group Author Rafael, José Albertino Instituto Nacional de Pesquisas da Amazônia, Coordenação de Entomologia, Caixa Postal 478, 69011 - 970, Manaus, Amazonas, Brazil. E-mail: jarafael @ inpa. gov. br Author Cumming, Jeffrey M. Invertebrate Biodiversity, Agriculture and Agri-Food Canada, K. W. Neatby Bldg, C. E. F., Ottawa, Ontario, Canada K 1 A 0 C 6. E-mail: jeff. cumming @ agr. gc. ca text Zootaxa 2009 2009-04-06 2064 1 39 56 https://biotaxa.org/Zootaxa/article/view/zootaxa.2064.1.4 journal article 10.11646/zootaxa.2064.1.4 1175-5326 5321572 Macrostomus melanothorax , n. sp. ( Figs. 3a–e , 8 ) Diagnosis. Thorax and abdomen shining black, legs predominantly yellow; postcranium black with gray pruinescence; male tergite 8 acute distally; vein CuA 1 longer than dm-cu vein. Female without pinnate scales on hind tibia; wing approximately as wide as male wing, rather hyaline. FIGURE 3 . Macrostomus melanothorax , n. sp. , holotype, male. A , wing; B , tergite 8, dorsal view with right setae omitted; C , dorsal part of epandrium and cercus, lateral view; D , hypandrium, lateral view. E , detail of the subapical process. Scales: B–D = 0.2 mm. Description. Holotype male. Frons approximately one third anterior ocellus width. Face slightly wider than frons only at ventral margin. Postcranium black. Antenna dark brown to black. Palpus brown. Thorax shining black with gray-brown pruinescence more distinct on disc of scutum. Seta: 4 dorsocentrals; 1 supraalar presutural; 1 pair of scutellar; 3–5 antepronotals; 1–3 tiny proepisternals; 4–5 katatergitals. Legs shining, yellow with apex of mid and hind femora, entire hind tibia and mid and hind tarsi black; fore tarsi yellow, tarsomeres 1–3 white apically. Hind tibia with three slender dorsal setae on distal half and first hind tarsomere with one longer setae dorsally. Wing ( Fig. 3a ) as described for M. fusciventris . Halter brown to black. CuA 1 vein longer than dm-cu vein. Abdomen shining black. Tergite 8 ( Fig. 3b ) acute distally. Epandrium with posterodorsal protuberance rather thin and higher than anterodorsal protuberance ( Fig. 3c ). Anterior cercus rather short; posterior cercus ramified with stout anterodorsal setae ( Fig. 3e ). Hypandrium ( Fig. 3d ) with a few setae at base, paired acute protuberances distally and two small protuberances laterally on each side and at distal third, and longer acute subapical process medially. Size. Body length 2.3 mm ; wing length 2.5 mm . Female. Frons approximately anterior ocellus width; face narrower than frons, approximately half anterior ocellus width; two pairs of scutellar setae; hind tibia with four slender dorsal setae and without pinnate scales. Terminalia similar to M. fuscithorax . Size. Body length 2.6 mm ; wing length 2.7 mm . Geographical records. Peru ( Madre de Dios province ), Brazil ( Amazonas state), Fig. 8 . Material. Holotype ♂ : BRASIL , Amazonas, Pq [Parque] N[acional] [do] Jau, Ig[arapé] Miratucu/ Ig[arapé] do Gerlei, 015700S–614900W, 23–28.vii.1985 // arm.[adilha] Malaise, J.A . Rafael & J.[F.] Vidal ( INPA ). Paratypes . Same data as holotype ( 1♀ INPA ); Manaus, PDBFF / WWF, Proj. Bert Klein, ix.1985 , Malaise , Res. 1301 ( 1♂ INPA ), Manaus , PDBFF / WWF, Proj. Bert Klein, xii.1985 ( 1♂ INPA ); PERU , Madre de Dios , Zona Reserva Manu , Pakitza , 400 m , 11 0 57’S –71 0 17’W , 13–23.ii.1992 , B. Brown & D. Feener , Malaise trap ( 1♀ USNM ) . Holotype condition. Right wing detached and glued on the pin. Terminalia in glycerin. Etymology. From Greek melanos = black, in reference to the black thorax. Discussion. Macrostomus melanothorax , n. sp. appears close to M. ferrugineus (Fabricius) , M. fuscithorax , n. sp. and M. fusciventris , n. sp. on the basis of the acute distal projection of male tergite 8. Macrostomus melanothorax shares a black thorax with M. fuscithorax , in contrast with the other species, which have a predominantly yellow thorax. It differs from M. fuscithorax by vein CuA 1 being longer than vein dm-cu, by the shape of the posterior cercus and apex of the epandrium, and by the hypandrium with its thinner and more acute apex.