Facitrichophora atrella, Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012, A revision of the new world species of Polytrichophora Cresson and Facitrichophora, new genus (Diptera, Ephydridae), ZooKeys 231, pp. 1-116 : 8-9

Facitrichophora atrella sp. n. Figs 15

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Generally black with tannish gray to silvery face and yellowish tarsomeres. Moderately small shore flies, body length 2.15-2.70 mm.

Head: Frons mostly black, generally very sparsely grayish microtomentose, becoming denser and tannish on and around ocellar triangle; fronto-orbits with silvery gray microtomentum. Antennal scape and pedicel black; basal flagellomere black or becoming tannish to brownish apically; arista bearing 5 dorsal rays. Face wide, microtomentum dull to subshiny, tannish gray to silvery. Parafacial concolorous with fronto-orbit. Gena moderately high, height equal to length of scape; gena-to-eye height ratio 0.20-0.28.

Thorax: Mesonotum subshiny to shiny, black, with sparse, whitish to grayish microtomentum; a single pair of posterior dorsocentral setae; no evident prescutellar acrostichal setae; scutellum trapezoidal in dorsal view with posterior margin truncate, lateral margins very slightly bowed, bearing 2 primary scutellar setae along lateral margins but also with several larger setae between primary setae, especially posteriorly. Wing uniformly faintly infuscate; costal vein ratio 0.57-0.60; M vein ratio 0.60-0.62.

Abdomen: Length of tergites 3 subequal to that of 2, tergite 4 slightly longer than 3, tergite 5 conspicuously longer than 4, triangular. Male terminalia (Figs 1-5): Epandrium narrowly connected dorsally above cerci (Figs 1-2), in posterior view (Fig. 1) pyriform or as an inverted pear, broadly oval on dorsal 3/4, bulged laterally at midheight, dorsal margin broadly rounded, ventral ¼ bilobed, as 2 straight, abutting, parallel-sided, moderately wide processes, width slightly less than that of cerci, each process bearing numerous small setulae, in lateral view (Fig. 2) epandrium and cerci together generally semicircular, cerci prominent, setulose, epandrium robustly developed, posterior margin arched, anterior margin irregularly straight with a shallow, pointed projection at midheight and shallowly sinuous; aedeagus simple, in lateral view (Fig. 4) elongate, narrow, tapered from base to apex, conspicuously curved, more so toward base, apex narrowly and bluntly rounded, in ventral view (Fig. 3) elongate, mostly parallel sided, tapered basally and apically, apex acutely pointed; phallapodeme in lateral view (Fig. 4) with distinct keel, keel angulate, both apices tapered, apex toward aedeagal base longer, parallel sided, digitiform, end toward hypandrium curved, tapered, in ventral view (Fig. 3) bar-like with lateral margins concave, gradually expanded toward each end, hypandrial end more abruptly expanded; gonite in lateral view (Fig. 4) rod-like, elongate, slender, shallowly sinuous, in ventral view (Fig. 3) relatively wide toward hypandrium, opposite end narrowed, digitiform; hypandrium in lateral view (Fig. 4) elongate, narrow, shallowly curved, narrowest at midlength, in ventral view (Fig. 3) more or less V-shaped with base well developed, wide, anterior margin rounded, each lateral arm oriented posterolaterally, robustly developed, apices truncate.

Type material.

The holotype male is labeled "COSTA RICA[,] Guanacaste Prov. Murciélago [10°56.9'N, 85°42.5'W;][,] 1 April 1988/Swept from sandy mud flats around mangrove inlet/W. E. Steiner[,] J. M. Hill[,] J. M. Swearingen[,] J. M. Mitchell/USNM ENT 00285972 [plastic bar code label]/HOLOTYPE ♂ Facitrichophora atrella Mathis & Zatwarnicki, USNM [red]." The holotype is double mounted (glued to a paper triangle), is in good condition (left wing partially torn), and is deposited in the USNM. Four paratypes (4♀; USNM) bear the same label data as the holotype. Other paratypes are as follows: COSTA RICA. Guanacaste: Nandayure, Puerto Thiel (10°01.6'N, 85°11.9'W; 0-20 m), 17 Oct 2003, W. Porras (2♂, 3♀; INBIO, USNM).

Other specimens examined.

COSTA RICA. Puntarenas: R. V. S. Golfito, Golfito, Llano Bonito (8°38.4'N, 83°11'W; mangal), 28 Apr 2004, W. Porras (2♀; INBIO).

Type locality.

Costa Rica. Guanacaste: Murciélago (10°56.9'N, 85°42.5'W; sandy mud flats around mangrove inlet).

Distribution

(Fig. 5). Neotropical: Costa Rica (Guanacaste, Puntarenas).

Etymology.

The species epithet, atrella, is of Latin derivation and refers to the blackish external appearance of this species.

Remarks.

Among congeners with a single posterior dorsocentral seta, this species is distinguished externally in having a mostly shiny black mesonotum that is very sparsely invested with grayish microtomentum. In addition, the scutellum has several lateral setae, especially posteriorly.