Macrostomus lineatus, 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 : 54-55

Macrostomus lineatus , n. sp.

( Figs. 12–19 , 40 )

Diagnosis. Postcranium black with no pruinosity on upper third; thorax yellow with a median black longitudinal stripe, this stripe internal to dorsocentral setae; no postsutural supra­alar seta; hind femur distinctly clavate; cell dm rather truncate; M1, M2 and A1 veins rather evanescent distally; epandrium with posterodorsal lobe wider than anterodorsal one, with spiniform setae internally.

Description. Male. Frons slightly narrower than anterior ocellus width. Face half of frons width. 1 pair of ocellar setae. Postcranium black with no pruinosity on upper third; postgena with tiny setae. Flagellum indistinctly trisegmented. Thorax yellow with a median black longitudinal stripe, this stripe internal to dorsocentral setae, extending from anterior margin of scutum to posterior pair of dorsocentral setae; gray­brown pruinose. 3– 4 dorsocentral setae, posterior pair longer; no postsutural supra­alar seta; 2 notopleural setae; 4–5 antepronotal setae; 2–3 proepisternal setae rather strong; 5–6 katatergital setae. Legs, yellow with apex of fore tibia, apex of mid femur, apex of mid tibia, apex of distinctly clavate hind femur, apex of hind tibia and mid and hind tarsi, black; fore tarsomeres 1–2 yellow. Slightly stronger setae: fore tibia with posterodorsal row with slightly longer slender setae; mid femur with 1 anterior near apex and 6–7 anteroventral slightly strong at distal third; mid tibia with 2 posterodorsal along basal half, 1 posterior at middle, 1–2 anteroventral very short at distal half; hind femur with 1 anterior near apex, 2 anteroventral at distal third, 4–5 posterior slender setae near base. Slender setae: hind tibia with 4 dorsal, two distal being longer; hind tarsomere 1 with 1 dorsal. Wing ( Fig. 12 ) brown­infuscated along costal and r1 cell and slightly at apex of r2+3 cell; cell dm rather truncate; M1, M2 and A1 veins rather evanescent distally. Halter yellow. Abdomen with T1 yellow laterally and no distinct longer posterolateral setae on T2–3. Terminalia ( Figs. 13– 15 ). Tergite 8 ( Fig. 13 ) with bifid distal projection and deep basal cleft. Epandrium ( Fig. 14 ) with posterodorsal lobe wider, slightly higher than anterodorsal lobe and with spiniform setae internally. Anterior cercus ( Fig. 14 ) short and narrow; posterior cercus complex, short with no setae distally; with a long and thin ventral protuberance with yellow digitiform setae at apex and internally with two short protuberances, one curved with longer yellow setae at apex and one, near base of the latter, not curved with small yellow setae at apex. Hypandrium ( Fig. 15 ) with few setae on basal third, a long projection medially. Ejaculatory apodeme narrowly connected to phallus.

Female. Frons slightly wider than anterior ocellus width; face half of frons width. Hind femur not as clavate as in male. Wing ( Fig. 16 ) more infuscated than in male. Female tergite 8 ( Fig. 17 ) with small cleft distally; sternite 8 ( Figs. 17, 18 ) with perpendicular median cleft laterally and a small sclerotized area internally. Genital fork ( Fig. 19 ) with small distal arms. Genital chamber membranous.

Size. Body length 3.8–3.9 mm; wing length 3.9–4.0 mm.

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

Material. Holotype ɗ: ECUADOR, Napo­Pastaza, 2–8 mi [les] N[orth] of Puyo, 953 m, II.9.1955 (sic), E.I. Schlinger & E.S. Ross coll (CAS). Paratypes. Same data as holotype (1Ψ CAS, same pin of the holotype); PERU, Avispas, Madre de Dios, 10– 20.ix.1962, L. Pena, 400 m (1Ψ CNC).

Holotype condition. Right antennae and abdomen in glycerine; right wing mounted in microslide.

Etymology. From Latin linea = line, in reference to the median dark stripe on scutum.

Discussion. As mentioned previously, M. lineatus apparently belongs to the same group as M. alpinus , M. ciliaticosta and M. tarsalis . All species possess a rather membranous area medially on the hypandrium. M. lineatus differs from the other species in having tergite 8 with a bifid distal projection and deep basal cleft, the hypandrium with a long projection medially and bearing a few setae on the basal third.

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 12 – 19. Macrostomus lineatus, n. sp. holotype ɗ and paratype Ψ. 12, male wing; 13, male tergite 8, dorsal view, right setae not represented; 14, male terminalia, lateral view, internal apex of epandrium in detail; 15, hypandrium and phallus, lateral view; 16, female wing; 17, female tergite 8 and sternite 8, lateral view; 18, female sternite 8, ventral view, left setae not represented; 19, female genital fork.