Mimapsilopa acta Mathis

Mathis, Wayne N., Costa, Daniel N. R. & Marinoni, Luciane, 2015, A review of Mimapsilopa Cresson (Diptera: Ephydridae) from Brazil, Zootaxa 3926 (4), pp. 499-522 : 503-504

Mimapsilopa acta Mathis , Costa & Marinoni n.sp.

Figs. 1–7 , 50 , 52 .

Diagnosis. This species is distinguished from congeners by the following combination of characters: Generally very dark brown, shiny; moderately small shore flies, body length 2.15–2.80 mm. Head ( Figs. 1–3 ): Frons dark brown, microsculptured. Basal flagellomere blackish dorsoapically, yellowish basoventrally, gradually tapered to rounded apex; arista with 9–10 dorsal rays. Face mostly shiny bluish black to black, microsculptured with shallow, mostly vertical striae. Eye ratio: 0.62–63; gena-to-eye ratio: 0.12–0.13. Thorax: Mesonotum sparsely microtomentose with brown microtomentum on shiny black background, appearing subshiny; anepisternum mostly shiny, only extreme margins microtomentose. Wing ( Fig. 50 ) mostly infuscate, anterior margin brown, becoming progressively lighter colored posteriorly, posterior margin largely hyaline; length 1.85–2.00 mm; costal ratio 0.61–0.68; M vein ratio 0.77–0.81. Knob of halter white, stem yellowish. Foreleg, including forebasitarsomere and femora, and tibiae of mid- and hindlegs dark brown to black; extreme apex of mid- and hindtibiae and mid- and hindtarsi yellow except for darkened apical tarsomere. Abdomen: Tergites sparsely microtomentose, mostly shiny; tergites 4, 5 about equal in length, both longer than tergite 3; tergite 5 bare, shiny. Male terminalia ( Figs. 4–7 ): Epandrium in posterior view ( Fig. 4 ) setulose with short, stout setulae, shape as an inverted, thick-walled U, widest at dorsolateral corners, slightly thinner at dorsal portion above cercal cavity, in lateral view ( Fig. 5 ) more or less rectangular dorsally, then becoming wider subventrally with anterior, relatively narrow protrusion, ventral margin nearly straight but slanted; cercus in posterior view ( Fig. 4 ) elongate, shallowly lunate but not sharply pointed at ventral and dorsal apices, in lateral view ( Fig. 5 ) semi-hemispherical; presurstylus symmetrical, in posterior view ( Fig. 4 ) with 2 short medial lobes, more medial lobe more robustly developed, bearing a stout, relatively long seta apically, other lobe short, apical seta shorter, large lateral lobe as wide as epandrial arm, slightly tapered ventrally, ventral margin rounded, in lateral view quadrate on basal half, thereafter apically thumb-like, broadly rounded apically; postsurstylus symmetrical, in lateral view ( Fig. 7 ), elongate, moderately narrow, lateral margins sinuous, lacking a rod-like, extended process; subepandrial plate in ventral view moderately and widely W-shaped, lateral arms curved medially, acutely pointed; aedeagus in lateral view ( Fig. 7 ) somewhat quadrate on basal half, apical portion narrower, thumb-like, apex rounded, in ventral view ( Fig. 6 ) elongate, base wide, apical third abruptly narrowed, narrowly digitiform; phallapodeme in lateral view ( Fig. 7 ) broadly lunate, extended keel wide but short, in ventral view ( Fig. 6 ) elongate, slender, with basal crossbar Y-shaped and subapical short crossbars; pre- and postgonite fused, in lateral view ( Fig. 7 ) a curved, rod-like process, bearing 2 setulae apically; hypandrium in ventral view ( Fig. 6 ) broadly and robustly U-shaped, especially thickened anteriorly, anterior margin bluntly rounded, lateral margin with angulate extension, thereafter posteriorly narrowed, almost parallel sided, posterior margin truncate, in lateral view ( Fig. 7 ) deeply pocket-like, anterior margin pointed, posterior margin extended as a tapered, narrow process toward phallapodeme.

Type material. The holotype male is labeled BRAZIL. Paraná: Matinhos, Rio da Onça [,] 25°47.1'S, 48°31.6'W; 3 m), 27 Jan 2010 [,] D. & W. N. Mathis/ Holotype ♂ Mimapsilopa acta Mathis , Costa, &Marinoni DZUP [red]. The holotype is double mounted (minuten in a block of plastic elastomer), is in excellent condition, and is deposited in DZUP. Seven paratypes (7♂; DZUP, USNM) bear the same label data as the holotype.

Etymology. The species epithet, acta , is of Greek derivation, meaning seashore or coast, and refers to the coastal habitat of this species in southern Brazil.

Type locality. BRAZIL. Paraná: Matinhos (Rio da Onça ; 25°47.1'S, 48°31.6'W; 3 m).

Distribution ( Fig. 52 ). Neotropical: Brazil (Paraná).

Remarks. This species is similar and is apparently closely related to M. cressoni Lizarralde de Grosso and M. bacoa Mathis and Zatwarnicki , but it is distinguished from either of these two species by structures of the male terminalia, especially the presurstylus, which is tapered apically and does not have a lateral incision.

Figures

FIGURE 52. Distribution map of Mimapsilopa. Mimapsilopa acta n. sp. (■); M. iguassu n. sp. (●); M. onssa n. sp. (♦); M. plaumanni n. sp. (■); M. rugosa n. sp. (▲); M. xingu n. sp. (●).

FIGURES 1 – 3. Mimapsilopa acta n. sp. (1) Head, anterior view; (2) Same, lateral view; (3) Same, oblique view. Scale bar = 0.2 mm.

FIGURES 4 – 7. Mimapsilopa acta n. sp. (4). Epandrium, cerci, presurstylus, posterior view. (5). Same, lateral view. (6). Aedeagus, hypandrium, phallapodeme, postsurstylus, pregonite, subepandrial plate, ventral view. (7). Same, lateral view. Scale bar = 0.1 mm.

FIGURES 46 – 51. Wings: (46) Mimapsilopa xingu n. sp.; (47) Mimapsilopa rugosa n. sp.; (48) Mimapsilopa onssa n. sp.; (49). Mimapsilopa iguassu n. sp.; (50). Mimapsilopa acta n. sp.; (51). Mimapsilopa plaumanni n. sp.