Hydrochasma glochium, Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2013

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2013, A revision of the shore-fly genus Hydrochasma Hendel (Diptera, Ephydridae), ZooKeys 363, pp. 1-161 : 44-46

15. Hydrochasma glochium sp. n. Figs 86-90

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small shore flies, body length 1.65-1.95 mm. Head: Antenna mostly dark gray; parafacial silvery white, concolorous with facial coloration; gena-to-eye ratio 0.19-0.21. Thorax: Wing with costal vein ratio 0.72-0.74; M vein ratio 0.50-0.53. Forecoxa whitish gray basally, apical 2/3-3/4 yellow; forefemur lacking a distinctive, comb-like row of stout setulae along anteroventral surface; tibiae mostly yellow; hindtibia with silvery gray, broad band medially. Abdomen: Tergites 3-4 with deep, silvery gray wedges laterally; tergite 5 mostly silvery gray, only anterior brownish black, and with faint blackish coloration posteriorly. Male terminalia (Figs 86-89): Combined structures generally moderately elongate, in posterior view height slightly less than 3 × width, generally sparsely setulose, more so dorsally, setulae sparse medially, setulae becoming smaller ventrally; epandrium lacking dorsal arch above cerci, in posterior view (Fig. 86) with apical 1/2 abruptly narrowed, mostly parallel sided, apical process conspicuously wider than apical 1/2, flared laterally subapically, apex with very narrow apicomedial V-shaped cleft, in lateral view (Fig. 87) elongate, narrow, generally shallowly curved, apical process with subapical expansion, apex bluntly rounded; aedeagus in lateral view (Fig. 89) very elongate and narrow, generally expanding toward apex, apical 1/2 with tiny, cuticular, narrow projections, apical 1/4 with complex folding, apex skewed anteriorly, narrowly pointed, in ventral view (Fig. 88) generally narrow and elongate, slightly narrowed at midlength, apical 1/3 slightly expanded, moderately bulbous, apex broad; phallapodeme in lateral view (Fig. 89) very narrow and elongate, rod-like to narrowly clavate, gradually expanded from aedeagal end to hypandrial end, latter with very narrowly pointed keel, aedeagal end straight, in ventral view (Fig. 88) elongate, narrow, truncate at both ends, slightly and gradually expanded at aedeagal end, hypandrial end with 2 narrow crossbars; gonite in lateral view (Fig. 89) as nearly straight, rod-like process, almost equal in length to phallapodeme, in ventral view (Fig. 88) nearly straight, very slightly wider medially, tapered at both apices; hypandrium in lateral view (Fig. 89) narrowly developed, posterior half narrowly angled, tapered toward anterior margin, narrowly angulate anteriorly, in ventral view (Fig. 88) moderately deeply and narrowly V-shaped, arms of V generally thick, pointed posteriorly, anteromedially margin bluntly rounded.

Type material.

The holotype male of Hydrochasma glochium is labeled "DOMIN[ICAN]. REP[UBLIC]. Peravia: San J[ osé] Ocoa,RioOcoa[,] 18°31.7'N, 70°30.4'W [,] 21May1998, WNMathis/USNM ENT 00087391 [plastic bar code label]/HOLOTYPE ♂ Hydrochasma glochium Mathis & Zatwarnicki, USNM [red]." The holotype is double mounted (minuten in a block of plastic), is in excellent condition (abdomen removed and dissected, parts in an attached microvial), and is deposited in the USNM. Paratypes are as follows: DOMINICAN REPUBLIC. La Vega: Salto Baiguate (near Jarabacoa; 19°05.5'N, 70°36.9'W; 570 m), 9 May 1995, W. N. Mathis (1♀; USNM). Pedernales: Cabo Rojo (26 km N; 18°06'N, 71°38'W; 730 m), 31 Jul 1990, J. E. Rawlins, S. Thompson, C. Young (1♂, 1♀; CMP).

Type locality.

Dominican Republic. Peravia: San José Ocoa (10 km NE; 18°35'N, 70°25.6'W).

Other specimens examined.

Neotropical. BOLIVIA. La Paz: Guanay (15°29.8'S, 67°52.7'W), 460 m), 13 Mar 2001, W. N. Mathis (2♂; USNM).

BRAZIL. São Paulo: Ubatuba, Praia Puruba (23°21'S, 44°55.6'W; beach), 29 Mar 2010, D. and W. N. Mathis (5♂; USNM).

COSTA RICA. Limón: Parque Nacional Cahuita, Sector Puerto Vargas (09°44'N, 82°49'W; 1 m), 27-28 Jun 2001, J. D. Gutierrez (1♂, 1♀; INBio).

ECUADOR. Orellana: RíoTiputini (0°38.2'S, 76°8.9'W), 12-26 Aug 1999, W. N. Mathis, A. Baptista, M. Kotrba (1♂; USNM).

VENEZUELA. Zulia: Carrasquero (11°02.1'N, 72°0.3'W), 29-30 May 1976, A. S. Menke, D. Vincent (1♂, 2♀; USNM).

West Indies. BARBADOS. Christ Church: Graeme Hall Swamp (13°04.2'N, 59°34.7'W), 2 Sep 1997, D. and W. N. Mathis (1♂; USNM).

Distribution

(Fig. 90). Neotropical: Bolivia (La Paz), Brazil ( São Paulo), Costa Rica ( Limón), Ecuador (Orellana), Venezuela (Zulia), West Indies (Barbados, Dominican Republic).

Etymology.

The species epithet, glochium, is of Greek derivation and means arrow head, referring to the arrow-like apex of the ventral extension of the epandrium.

Remarks.

In the remarks section of the previous species (p. 61), we noted characters to distinguish this species from Hydrochasma falcatum , particularly the more pronounced, lateral extensions of the apical portion of the ventral, the epandrial process, and the robust, V-shaped, hypandrium. (Figs 86-88).