Neomuscina nigricosta Snyder 1949

Neomuscina nigricosta Snyder, 1949

(Figs. 71–76)

Neomuscina nigricosta Snyder 1949: 5 (key), 22 (description); Snyder 1954: 425 (key); Pont 1972: 50 (catalogue); de Carvalho et al. 1993: 58 (catalogue); Couri & de Carvalho 2002: 152 (key); de Carvalho et al. 2005: 95 (catalogue).

Diagnosis: acrostichal 0:1; dorsocentral 2:4; mid femur with two preapical setae; hind tibia with one median anterodorsal setae; wing hyaline, with dark cloud running continuously from Sc to R2+3 apex.

Color: general body coloration brownish yellow; frons yellow, apex darkened; facialia and parafacialia white; gena, antenna and palpus yellow; scutum with four light stripes of grey pruinosity; calypters and halter yellow; wing hyaline, with dark cloud running continuously from Sc to R2+3 apex; dark cloud on R1 running down and joining with a cloud on r-m; dm-cu with a dark cloud; posterior half of wing distinctly darker than anterior half (Fig. 136).

Male. Length. Body: 6.6–7.1 mm; wing: 6.4–7.0 mm.

Head: eyes separated from each other by 0.14–0.17 mm, at level of ocellar tubercle; six pairs of convergent frontal setae; ocellar seta large and parallel; postocellar seta large and divergent; inner vertical seta small and convergent; outer vertical seta small and divergent.

Thorax: acrostichal 0:1; dorsocentral 2:4; intra-alars 2; fore tibia with a distinct median anterodorsal setae; apex of fore tibia with setae on anterior, posterodorsal, posteroventral surfaces; mid femur with a row of setae on ventral surface from base to middle; mid femur with two preapical setae, on posterodorsal and posterior surfaces; apex of mid tibia with setae on anterior, dorsal, posterodorsal, posteroventral, ventral and anteroventral surfaces; hind femur with a complete row of dorsal and anteroventral setae, and a row of posteroventral setae from base to middle; hind tibia with one median anterodorsal setae and two median anteroventral setae; hind tibia with anterior, anterodorsal, dorsal, posterodorsal, ventral and anteroventral setae at apex; wing with one dorsal and two ventral setae at apex of stem vein.

Abdomen: epandrium with basal projection; cercus with apex excavated.

Female (differing as follows): Length. Body: 6.6–7.2 mm; wing: 6.4–7.2 mm; eyes separated from each other by 0.28–0.31 mm, at level of ocellar tubercle; 9–10 pairs of frontal convergent setae, except for upper two pairs, parallel; ocellar seta large and postocellar seta small, both divergent; inner vertical seta large and convergent, and outer vertical seta large and divergent; sternites VI and VII strongly sclerotized; segments VI and VII with many dorsal and ventral setae; sternite VIII with spike-like setae; epiproct with four setae, setae in a square-shaped arrangement (2:2).

Comments: N. nigricosta is easily distinguished from other species by the presence of a strong dark cloud from Sc to the apex of R2+3, without interruption. This is the first record of this species in Brazil.

Holotype (not examined): AMNH. Type-locality: Port of Spain, Trinidad and Tobago.

Material examined: BRAZIL. Mato Grosso. 1 male and 1 female “ DPTO ZOOL / UF-PARANÁ | Chap. Guimarães – MT / 22.XI.1983 / Exc. Dep. Zool. – UFPR / POLONOROESTE” (DZUP) \ 2 males and 1 female, same locality and collector, 23.XI.1983 (DZUP) \ 1 female, same locality and collector, 24.XI.1983 (DZUP) \ 1 male, same locality and collector, 30.XI.1983 (DZUP) \ 3 males and 3 females, same locality and collector, 01.XII.1983 (DZUP) \ 6 males and 14 females, same locality and collector, 02.XII.1983 (DZUP) \ 2 males, same locality and collector, 03.XII.1983 (DZUP) \ Roraima. 1 male “ BRASIL, Roraima / Rio Uraricoera / Ilha de Maraca / 02–13.V.1987 | Armadilha / de Shannon | J.A. Rafael / J.E.R. Brasil / L.S. Aquino” (DZUP).

Geographical distribution: Brazil (Roraima and Mato Grosso [new localities]), Guiana, Trinidad and Tobago (type-locality).