Macrostomus ciliaticosta, Rafael, José Albertino & Cumming, Jeffrey M., 2006

Rafael, José Albertino & Cumming, Jeffrey M., 2006, New species of Macrostomus Wiedemann (Diptera, Empididae) from Colombia, Ecuador and Peru, Zootaxa 1136, pp. 49-64 : 52-54

Macrostomus ciliaticosta , n. sp.

( Figs. 5–11 , 40 )

Diagnosis. Thorax yellow with scutum and scutellum brown to black; female with short dorsal pinnate scales on hind tibia; cell dm rather acute; M1, M2 and A1 rather distinct.

Description. Male. Frons one­third of anterior ocellus width. Face slightly wider than frons. 2 pairs of ocellar setae. Flagellum indistinctly trisegmented. Thorax yellow with scutum and scutellum brown to black, more distinctly gray­brown pruinose on darker areas. 3 dorsocentral setae, the mid one weaker; 3 notopleural setae; 3–4 antepronotal setae; 1–2 proepisternal setae rather strong (when 2, one smaller); 7–8 katatergital setae. Legs, predominantly yellow with apex of fore tibia, apex of mid femur, apex of mid tibia, distal half of hind femur, entire hind tibia and mid and hind tarsi, black; fore tarsomeres 1– 3 rather yellow, 1–2 light banded medially, 4–5 black. Slightly stronger setae: fore tibia with 1–2 posterodorsal along basal half; mid femur with 1 anterior near apex; mid tibia with 2 anterodorsal near base and slightly beyond middle, 1 posterodorsal at middle, 2 posteroventral along basal half, 3–4 anteroventral along distal three­quarter; hind femur with 3 anterior at basal three­quarter, near base of distal third and at distal three­quarter, 2– 3 anteroventral along distal third. Slender setae: hind tibia with 5–6 dorsal; hind tarsomere 1 with 2 dorsal. Wing ( Fig. 5 ) brown­infuscated along costal cell and apex of cell r2+3; cell dm rather acute; M1, M2 and A1 rather distinct; costal vein with longer slender setae at base. Halter whitish at apex of knob. Abdomen black. Terminalia ( Figs. 6–8 ). Tergite 8 (fig. 6) with truncated distal projection. Epandrium ( Fig. 7 ) with anterodorsal and posterodorsal lobes of subequal height. Anterior cercus ( Fig. 7 ) short and narrow; posterior cercus with apex acute and few long slender setae at margin, with wide ventral protuberance with many marginal yellow setae. Hypandrium ( Fig. 8 ) with distinct bifid protuberance posteriorly, many setae along posterior margin.

Female. Frons approximately anterior ocellus width; face slightly narrower than frons. Fore tibia with 1 longer posterodorsal seta near middle; hind femur with 2 anterior setae near base and near apex; hind tibia ( Fig. 9 ) with 4 dorsal setae and short dorsal pinnate scales; hind tarsomere 1 with 1 slender dorsal seta. Wing distinctly long. Female tergite 8 as in Fig. 10 ; sternite 8 ( Fig. 11 ) with subapical paired sclerotized protuberance, medially with a longitudinal rather membranous line, laterally less sclerotized and at distal half with a lateral area more sclerotized. Genital fork Y­shaped with rather strong lateral arms and a median short protuberance ventrally. Genital chamber membranous.

Size. Body length 3.8–4.0 mm; wing length 4.1–5.3 mm.

Geographical distribution. Ecuador, Peru, Brasil ( Fig. 40 ).

Material. Holotype ɗ: PERU, Cuzco, Quincemil, 01–15.xi.1962, L. Pena, 700 m (CNC). Paratypes. Same data as holotype (2ɗ CNC); 15–30.x.1962 (1ɗ INPA); ECUADOR, Tixan, 8 mi [les]. NE Alausi, Chimborazo, II.14.1955 (sic), 2800 m, E.I. Schlinger & E.S. Ross coll. (1Ψ CAS); BRAZIL, Amazonas, Coari, Rio Urucu, Petrobrás, RUC 30, 27.x –01.xi.1994, L.E.F. Rocha e Silva, arm. Malaise (1Ψ INPA).

Holotype condition. Not dissected.

Etymology. From Latin cilium = ciliate, costa = costa, in reference to the longer setae on C vein.

Discussion. M. ciliaticosta apparently belongs to the same group as M. alpinus , M. lineatus and M. tarsalis , because each species has a rather membranous area medially on the hypandrium. M. ciliaticosta differs in having tergite 8 with a small truncated projection, the hypandrium bearing a distinct bifid protuberance and in possessing slender setae along entire posterior margin.

Figures

FIGURE 40. Distributions of new species of Macrostomus. Symbols represent the known collection localities as follows: square = M. alpinus; diamond = M. ciliaticosta; circle = M. lineatus; star = M. occidentalis; triangle = M. penai; cross = M. tarsalis.

FIGURES 5 – 11. Macrostomus ciliaticosta, n. sp. paratype ɗ and paratype Ψ. 5, male wing; 6, male tergite 8, dorsal view, right setae not represented; 7, male terminalia, lateral view; 8, hypandrium and phallus, lateral view; 9, female left hind leg, anterior view, larger and pinnate setae represented; 10, female tergite 8, dorsal view, setae not represented; 11, female sternite 8, right setae not represented.