Planinasus neotropicus, 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 : 19-23

3. Planinasus neotropicus sp. n. Figures 15-19

Description.

Small to moderately small flies, body length 1.80-2.55 mm.

Head: Frons mostly bare, shiny, except for densely microtomentose, velvety-appearing, anterolateral angles; frons slightly wider than long, frontal ratio averaging 0.65; interfrontal seta short, about 1/2 length of lateral vertical seta. Antenna unicolor ous, blackish brown; pedicel with ventral projection short, not extended anteriorly much beyond dorsal margin; basal flagellomere short, width about 2/3 length; arista bearing 8-9 dorsal rays, 3-4 ventral rays. Face comparatively narrow; facial ratio averaging 0.25; dorsal half of face shield-like, mostly bare, roughly pentagonal, with yellowish to slightly bluish reflections; facial setae more or less in 2 transverse rows, dorsal row with 4 setae, 2 dorsoclinate, 2 ventroclinate; ventral facial row with 4 ventroclinate setae. Clypeus and palpus blackish brown.

Thorax: Generally dark brown but with some paler, mostly yellowish areas along margins of sclerites; mesonotum moderately invested with whitish gray microtomentum, appearing dull medially, becoming subshiny, less microtomentose laterally; postpronotum yellowish; area from postpronotum and through notopleuron mostly bare, shiny; anepisternum moderately invested with very fine microtomentum, mostly appearing dull; other pleural areas less densely invested. Wing very faintly infumate, without pattern. Coxae whitish yellow; femora whitish yellow basally, distal 1/2-1/3 dark brown; forefemur lacking a preapical annulus; basal 1/3 of tibiae dark brown, thereafter gradually becoming yellowish; tarsi yellowish, apical 2-3 tarsomeres darker; forefemur bearing 2 setae at apical 1/3 along posteroventral surface.

Abdomen: Uniformly blackish brown, mostly subshiny, moderately invested with microtomentum. Male abdomen: Tergites 1+2-6 well developed, lengths of tergites 3-6 subequal; sternite 3 only slightly wider than long, posterior margin sinuous with a medial, moderately broad, rounded projection; sternite 4 with width over twice length, sclerotized portion deeply emarginate, widely W-shaped with broad portion membranous posteriorly; sternite 5 with width over twice length, anterior margin with shallow, medial depression, lateral margins becoming slighter wider posteriorly, posterior margin shallowly emarginate, posterolateral corners rounded; sternite 6 apparently absent; sternite 7 well developed but narrow, forming an annulus with tergite 7. Male terminalia (Figs 15-18): Epandrium in lateral view (Fig. 15) narrowly trapezoidal, dorsal margin truncate, straight; surstylar length slightly less than half length of epandrium, extended from ventral margin of epandrium, in nearly vertical alignment with epandrium, in lateral view (Figs 15-16) digitiform on apical 2/3, with anterior and posterior basal margins bulged, apex bluntly rounded to truncate, bearing 1 large, sub-basal setula; hypandrium in ventral view (Fig. 16) V-shaped with anterior, angulate portion of V thickened; postgonite in ventral view (Fig. 16) convoluted, with robustly developed lobe expanded apically, invested with numerous setulae, lobe in lateral view (Fig. 18) irregularly clavate with uneven expansion, apical portion bearing approximately 20 setulae; phallus large, in ventral view (Fig. 16) complex, partially sclerotized; phallapodeme in lateral and ventral views (Figs 16, 18) elongate, tubular, truncate apically; ejaculatory apodeme in lateral view (Fig. 17) long, length subequal to that of phallapodeme, clavate, apex only moderately expanded.

Type material.

The holotype male is labeled "PANAMA: CANAL ZONE Barro Colorado Isl. 28. June. [day and month handwritten] 1978 N.E.Woodley/Malaise trap/USNM ENT 00118285 [plastic bar code label]/HOLOTYPE ♂ Planinasus neotropicus Mathis & Rung USNM [red]." The holotype is double mounted (minuten wired to a larger pin), is in good condition (some setae missing), and is deposited in the USNM. Paratypes are as follows: PANAMA. Balboa (08°57'N, 79°34'W), Feb 1958, M. R. Wheeler (1♂, 1♀; USNM). Fort Davis (09°17.3'N, 79°54.4'W), 28 Aug 1952, F. S. Blanton (1♀; USNM). Fort Sherman, Mojinga Swamp (09°18.2'N, 79°57.9'W), 30 Jan 1952, F. S. Blanton (1♂; USNM). Gamboa, Rio Agua Salud (09°07.1'N, 79°41.6'W), Jul 1967, W. W. Wirth (1♂; USNM). Las Cruces Trail (09°07.3'N, 79°42.7'W), Feb 1958, M. R. Wheeler (3♂, 2♀; USNM). Monte Lirio (08°57.5'N, 82°49.5'W), 6 Apr 1923, R. C. Shannon (1♀; USNM).

Type locality. Panama. Canal Zone: Barro Colorado Island (09°09.1'N, 79°50.8'W).

Other specimens examined.BELIZE. Stann Creek: Cockscomb Basin Wildlife Sanctuary (16°47'N, 88°30'W), 5-6 Apr 1993, W. N. Mathis (3♂; USNM).

BOLIVIA. La Paz: Apa Apa (8 km S Chulumani; 16°35.6'S, 68°51.2'W; 3840 m), 10 Mar 2001, W. N. Mathis (1♀; USNM); Mapiri (15°18.6'S, 68°13'W; 720 m), 15 Mar 2001, W. N. Mathis (1♂; USNM); Mapiri (5 km W; Arroyo Tuhiri; 15°17.8'S, 68°15.6'W; 750 m), 16 Mar 2001, A. Freidberg, W. N. Mathis (16♂, 10♀; USNM).

COSTA RICA. Cartago: Tapanti National Park (08°47.7'N, 83°55.6'W; wet log over stream), 11 Oct 1999, S. A. Marshall (2♂, 2♀; DEBU). Guanacaste: Pitilla (9 km S Santa Cecilia; 10°59.5'N, 85°25.8'W; 700 m), 21 Feb 1996, S. A. Marshall (1♂; DEBU). Heredia: La Virgen del Socorro (10°16.8'N, 84°10'W; 700 m; swept over wet leaf litter), 17 Mar 1991, D. A. Grimaldi, J. Stark (4♂; AMNH). Limón: Bribri (4 km NE; 09°37.5'N, 82°49.8'W; 50 m), Dec-Mar, 1989, 1990, P. Hanson (1♂; DEBU). Puntarenas: Peninsula de Osa, Rincón (08°42.5'N, 83°29.2'W; palm-mangrove forest; sea level), 24 Mar 1991, D. A. Grimaldi, J. Stark (3♂, 4♀; AMNH); Rincón (5 km S; 08°42.1'N, 83°30.8'W; 95 m), 10-11 Aug 2001, D. and W. N. Mathis (2♂, 7♀; USNM); R. F. Golfo Dulce (24 km W Piedras Blancas; 08°47.2'N, 83°19.3'W; 200 m), Nov 1990, P. Hanson (2♀; DEBU).

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♂, 16♀; USNM, ZSMC).

PERU. Cuzco: Quincemil (13°13.7'S, 70°45.6'W; 740 m), Aug 1962, L. E. Peña (2♂, 3♀; CNC). Madre de Dios: Río Manu, Pakitza (11°56.6'S, 71°16.9'W; 250 m), 9 -23 Sep 1988, A. Freidberg, W. N. Mathis (17♂, 11♀; USNM); Río Manu, Erika (near Salvación; 12°50.7'S, 71°23.3'W; 550 m), 5-6 Sep 1988, A. Freidberg (2♂, 2♀; USNM).

VENEZUELA. Aragua: H. Pittier National Park (6 km N Rancho Grande Biological Station; 10°21.2'N, 67°42.9'W; along stream), 28 Feb 1995, S. A. Marshall (2♂; DEBU).

Distribution

(Fig. 19). Neotropical : Belize, Bolivia (La Paz), Costa Rica (Cartago, Guanacaste, Heredia, Limón, Puntarenas), Ecuador (Orellana), Panama, and Peru (Cuzco, Madre de Dios), Venezuela (Aragua).

Etymology.

The species epithet, neotropicus, is to recognize the Neotropical distribution of this species and is a noun in apposition.

Remarks.

This species, like Planinasus ambiguus , is relatively widespread, especially in Andean countries. It can be easily confounded with the other two species in the ambiguus group based on external characters. See “Remarks” under Planinasus aenigmaticus sp. n. for further discussion on how to distinguish among Planinasus aenigmaticus sp. n., Planinasus ambiguus and Planinasus neotropicus sp. n.

The shannoni group

Included species. Planinasus kotrbae sp. n., Planinasus miradorus sp. n., Planinasus shannoni (Malloch), Planinasus tobagoensis sp. n., Planinasus venezuelensis Hennig, and Planinasus xanthops sp. n.

Diagnosis. This species group is distinguished by the following combination of characters: Head: Interfrontal seta long, subequal to length of lateral vertical seta. Antennal coloration variable; pedicel with elongate ventral projection; basal flagellomere long, length nearly twice height. Large facial setae arranged in 2-3 transverse rows; face of females bulbous, evenly transversely arched, mostly black. Thorax: Anepisternum with 2-4 weak setae along posterior margin. Wing strongly infumate. Forefemur of male lacking a preapical yellowish annulus, bearing 1 large, posteroventral seta at apical 1/3. Abdomen: Surstylus generally without posterior processes or lobes ( Planinasus kotrbae has a process), in nearly oblique alignment with anterior margin of epandrium (except in Planinasus tobagoensis ); postgonite with small, finger-like lobe bearing a few apical setulae; phallus mostly membranous (more heavily sclerotized in Planinasus shannoni ); ejaculatory apodeme generally reduced, inconspicuous in some species.

Discussion. The species of this group demonstrate considerable sexual dimorphism. The dimorphism is most evident in the shape and coloration of the face. The shape and coloration of the male face varies, depending on the species, but the face of females is quite similar in three species and is generally dark colored and conspicuously projected forward, bulbous, evenly arched transversely, somewhat flat in lateral view on ventral half. Species of this group share, with species of the atriclypeus group and with Planinasus obscuripennis sp. n. (the obscuripennis group) the reduced number of setae on the postgonite (2-6), and the ejaculatory apodeme is generally reduced or inconspicuous. In other species of Planinasus , the lobe of the postgonite, which is generally better developed, bears more than 20 setulae, and the ejaculatory apodeme is large, with a fan-like apical expansion.