Planinasus tobagoensis, Mathis, Wayne N., Rung, Alessandra & Kotrba, Marion, 2012

Mathis, Wayne N., Rung, Alessandra & Kotrba, Marion, 2012, A revision of the genus Planinasus Cresson (Diptera, Periscelididae), ZooKeys 225, pp. 1-83 : 33-36

7. Planinasus tobagoensis sp. n. Figures 39-43

Description of male.

Moderately small to medium-sized flies, body length 2.10-3.10 mm.

Head: Head ratio 0.53-0.56; frons mostly bare of microtomentum, shiny, except for densely microtomentose, velvet-like, anterolateral corner, blackish brown; frons much wider than long, frontal ratio 0.35-0.37; interfrontal seta long, length subequal to that of lateral vertical seta. Antenna blackish brown; pedicel with ventral projection moderately long, about 1/2 length of basal flagellomere; basal flagellomere long, length slightly more than twice basal width; arista bearing 13-14 dorsal rays, 3-4 ventral rays. Face very wide, facial ratio 0.81-0.83; face dorsad of transverse carina, including antennal grooves, mostly black to deep bluish black, face ventrad of transverse carina with broad mediovertical, black vitta, ventrolateral portion of face becoming progressively lighter in color, yellowish laterally; parafacial yellow; large facial setae 4-5 on each side, 2 medial, porrect to shallowly ventroclinate setae in vertical alig nment, larger seta ventrad; next seta toward lateral margin dorsoclinate to inclinate, aligned with dorsal medial seta; next 2 lateral setae, more or less aligned vertically, both shallowly ventroclinate. Clypeus and palpus blackish brown. Gena concolorous with lateral margin of face.

Thorax: Mesonotum generally brownish black to deep bluish black, very thinly microtomentose, subshiny to mostly shiny; postpronotum dark brown with some yellowish coloration around margin; area from postpronotum and through notopleuron mostly bare, finely microtomentose, dull to subshiny; pleural areas finely microtomentose, dull, blackish brown; anepisternum mostly bare except for 2-3 setulae along posterior margin; katepisternum generally setulose, bearing 2 setae toward dorsal margin. Wing without pattern, generally infumate, slightly more so anteriorly, base hyaline. Coxae and trochanters whitish yellow to yellow; femora and tibiae uniformly brownish black; forefemur with preapical, pale annulus lacking or weakly indicated; tarsi mostly yellowish, apical 1-2 tarsomeres becoming darker; forefemur bearing 1 seta at apical 1/3 along posteroventral surface.

Abdomen: Uniformly blackish brown to black, mostly shiny, very sparsely invested with microtomentum. Male abdomen: Tergites 1+2-6 well developed, lengths of tergites 3-6 subequal; tergite 7 narrow; sternites 3, 4, 5 generally as rectangular plates, slightly wider than long, lateral margins shallowly arched; no sternites 6, 7, neither segment forming an annulus. Male terminalia (Figs 39-42): Epandrium in lateral view (Fig. 39) trapezoidal, higher than wide, anterior and posterior margins nearly straight, dorsal margin short, length slightly less than surstylar width at base, slightly arched; surstylus as long as epandrium, in lateral view (Fig. 39) extended from ventral margin of epandrium in nearly vertical alignment with it, tapered, anterior margin arched, especially subapically, posterior margin shallow sinuous, apex acutely pointed, bearing 1 large, medial setula; hypandrium in ventral view (Fig. 40) more or less V-shaped, arms in ventral view (Fig. 40) thin at attachment with epandrium, anterior margin thickened anteromedially, broadly pointed, forming a right angle; pregonite irregularly shaped, roughly diamond-shaped (Fig. 40); postgonite in ventral view (Fig. 40) convoluted, bearing lobe with setae, in lateral view (Fig. 42) lobe bearing 2 apical setulae; phallus in ventral view (Fig. 40) complex, mostly membranous, in lateral view (Fig. 42) thumb-like, bearing tiny setulae; phallapodeme in lateral and ventral views (Figs 40, 42) elongate, tubular, nearly straight, bluntly rounded apically; ejaculatory apodeme much reduced, length subequal to ½ length of phallapodeme, in lateral view (Fig. 41) with basal half enlarged, basal margin deeply incised, apical half narrow, rod-like, lacking fan-like process.

Description of female.

Same as male except as follows: Head: Head ratio 0.70-0.74; frontal ratio 0.43-0.45; face and antenna mostly blackish brown, lateral margin of face (immediately adjacent to parafacial) whitish yellow; face not as wide, facial ratio 0.43-0.45; face projected forward on ventral 1/2, bulbous, evenly arched transversely, shallowly arched vertically, mostly flat.

Type material.

The holotype male is labeled "TOBAGO. St. John: Parlatuvier (11°18'N, 60°39'W), 14 Jun 1993, W.N. Mathis/USNM ENT 00118281 [plastic bar code label]/HOLOTYPE ♂ Planinasus tobagoensis Mathis & Rung USNM [red]. The holotype is double mounted (minuten pin in a plastic block), is in excellent condition, and is deposited in the USNM. Seven paratypes (3♂, 4♀; USNM) bear the same locality data as the holotype but with dates from 20 Apr– 14 Jun 1993, 1994. Other paratypes are as follows: TRINIDAD and TOBAGO. Tobago. St. John: Charlotteville (2 km S; 11°19'N, 60°33'W), 10 Jun 1993, W. N. Mathis (1♀; USNM). St. Paul: Argyle Falls (11°15'N, 60°35'W), 21 Apr 1994, W. N. Mathis (1♂; USNM); Roxborough (6 km NNW; 11°16'N, 60°35.4'W), 20 Apr 1994, W. N. Mathis (1♂; USNM); Roxborough (6.5 km N; 11°17'N, 60°35'W), 14 Jun 1993, W. N. Mathis (1♂; USNM). TRINIDAD. St. George: Mount St. Benedict (10°39'N, 61°24'W), 18-21 Jun 1993, W. N. Mathis (2♂, 1♀; USNM).

Type locality.

Trinidad and Tobago. Tobago. St. John: Parlatuvier (11°17.9'N, 60°39'W).

Other specimens examined.

ECUADOR. Orellana: Rio Tiputini Biodiversity Station (0°38.2'S, 76°8.9'W), 12-26 Aug 1999, A. Baptista, M. Kotrba, W. N. Mathis (1♀; ZSMC).

GUYANA. Kumu River and Falls (25 km SE Lethem in Kanuku Mountains; 3°15.9'N, 59°43.6'W), 28-30 Apr 1995, W. N. Mathis (1♀; USNM).

Distribution

(Fig. 43). Neotropical: Ecuador (Orellana), Guyana, Trinidad and Tobago.

Etymology.

The specific epithet, tobagoensis, is to recognize the island where the type locality is located.

Remarks.

This species is known from northern South America, including Trinidad and Tobago. It keys out near Planinasus kotrbae . Besides the characters given in the key, it can be easily distinguished from that species by the absence of a basal process on the surstylus and a roughly diamond-shaped pregonite (roughly triangular in Planinasus kotrbae ).