Polytrichophora agens Cresson

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 : 23-27

Polytrichophora agens Cresson Figs 2937

Polytrichophora agens Cresson 1924: 161; 1942: 114 [review of Nearctic fauna]. Wirth 1956: 9 [list, Bahamas]; 1965: 740 [Nearctic catalog]; 1968: 8 [Neotropical catalog]. Mathis and Zatwarnicki 1995: 183-184 [world catalog]. Mathis 1997b: 36-39 [review, Belize].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Moderately small shore flies, body length 2.30-2.90 mm (comparatively large and robust in comparison to congeners).

Head (Figs 29-30): Frons dull, heavily microtomentose, 2-toned, mostly tan with some faint golden reflections on posterior 2/3, anterior 1/3 (from level of fronto-orbital setae anteriad), gray. Antenna mostly yellow to yellowish orange, anterior portion of pedicel and basodorsal area of basal flagellomere with some blackish coloration; arista with 5 dorsal rays. Face at narrowest point about equal to combined length of pedicel and basal flagellomere; face densely microtomentose with subshiny to pearly luster, mostly white but with considerable gold coloration in antennal grooves and extended laterally onto parafacial; parafacial color not markedly differing from midfacies; parafacial becoming much wider ventrally and with slight to considerable ventral dilation, 2-3 times wider ventrally than dorsally; gena moderately high, height about equal to combined length of pedicel and basal flagellomere; gena-to-eye ratio 0.20-0.23.

Thorax (Fig. 31): Mesonotum mostly dull, densely microtomentose, concolorous with posterior 2/3 of frons; pleural area blackish gray. Anterior margin of wing lacking spine-like setae; costal vein ratio 0.54-0.58; M vein ratio 0.55-0.58. Forefemur lacking a row of 9-10 short, stout setulae along apical half of anteroventral surface; forefemur with a row of 7-9, of mostly elongate, well-developed, evenly spaced posteroventral setae, each equal to width of femur; tibiae mostly yellowish; basal tarsomeres yellow, apical 1-2 brown.

Abdomen: Tergites dull to subshiny, gray to blackish brown; tergites 1-4 bicolored, mostly blackish brown dorsally, gray lateroventrally; tergites 3-4 of male subequal, 4th not unusually longer, tergite 3 not produced ventrolaterally; dorsum of tergite 5 of male not darker than preceding tergites and usually with distinct, semicircular, grayish areas laterally; tergite 5 of male in dorsal view not markedly narrowed posteriorly, bearing row of 6-10, distinctly larger setae along extreme posterior margin with posterodorsal orientation; tergite 5 of male also gray on posterior 1/2-1/3; male sternite 1 transversely rectangular; sternite 2 much longer than wide, narrowly triangular, wider anteriorly, anterior margin emarginate; sternite 3 longer than wide, more robust than sternite 2, lateral margins shallowly arched, nearly parallel sided; sternite 4 robustly T-shaped, with posterior, transverse bar; sternite 5 as 2, narrow, bar-like sternites. Male terminalia (Figs 32-36): Many structures asymmetrical; epandrium asymmetrical (Fig. 32), connected dorsally above cerci, in posterior view (Fig 32) tapered ventrally to an acutely pointed apex under which lies cordate-shaped, laterally flanged anterior margin (Fig. 32); epandrium in lateral view (Fig. 33) slightly curved anteroventrally, pointed apically, and with subapical ledge that also ends ventrally in a point; gonite in lateral view (Fig. 36) mostly rod-like, obtusely angled, end toward aedeagal base slightly enlarged, clavate; aedeagus with distinct basiphallus and distiphallus, in lateral view (Fig. 36) basiphallus somewhat tubular but lacking digitiform projection at apex, in ventral view (Fig. 35) narrowly cordate; distiphallus more membranous, contorted and sinuous, asymmetrically bifurcate apically (Figs 35-36); phallapodeme in lateral view (Fig. 36) as a curved, narrow, rod with keel essentially undeveloped, in ventral view (Fig. 35) asymmetrical, as a curved rod; hypandrium in lateral view (Fig. 36) short, rod-like, enlarged toward anterior margin, in ventral view (Fig. 35) transversely crescent shaped, narrow.

Type material.

The holotype female is labeled "Galveston J[u]n[e] [19]00 Tex[as]/W. M. Wheeler Collection./Holo-TYPE Polytrichophora AGENS E. T. Cresson Jr [maroon; species name handwritten]. The holotype is double mounted (pin in a rectangular card), is in good condition, and is deposited in the AMNH.

Type locality.

United States. Texas. Galveston (29°18.1'N, 94°47.9'W).

Other specimens examined.

Nearctic. UNITED STATES. DELAWARE. Sussex: Rehoboth (38°43.2'N, 75°04.6'W), 25 Jun 1939, A. L. Melander (1♀; ANSP).

FLORIDA. Lee: Fort Myers (26°38.4'N, 81°52.3'W), 24 Apr 1930, A. L. Melander (1♂; ANSP). Monroe: Bahia Honda Key (24°40.1'N, 81°15.9'W; seashore), 11 Apr 1970, W. W. Wirth (3♂, 2♀; USNM); Big Pine Key, Long Beach (24°38.1'N, 81°21.6'W), 11 Feb 2000, D. and W. N. Mathis (20♂, 5♀; USNM); Flamingo, Everglades National Park (25°18.8'N, 80°56.2'W), 25 Jan 1939, A. L. Melander (1♂, 2♀; ANSP); Layton (Long Key; (24°49.9'N, 80°48.3'W), 10 Feb 2000, D. and W. N. Mathis (1♀; USNM); Sugarloaf Key (24°38.6'N, 81°30.9'W), 11 Feb 2000, D. and W. N. Mathis (2♂, 1♀; USNM).

MISSISSIPPI. Jackson: Ocean Springs, Marsh Point, Gulf Coast Research Laboratory (30°23.6'N, 88°47.8'W), 4-6 Jun 1962, D. L. Deonier (16♂, 165♀; USNM).

NORTH CAROLINA. Brunswick: Southport (33°55.3'N, 78°01.2'W), 19 Apr 1989, D. and W. N. Mathis (7♀; USNM).

TEXAS. Aransas: Aransas State Park (28°08.1'N, 96°58.9'W), 20 May 1972, W. W. Wirth (1♀; USNM). Galveston: Galveston (29°18.1'N, 94°47.9'W), Jan 1900, W.M. Wheeler (1♂, 1♀; ANSP); Galveston Island (29°10'N, 94°05'W), 14 May 1993, D. and W. N. Mathis (1♂; USNM).

VIRGINIA. Accomack: Assateague Island, Toms Cove (37°53.3'N, 75°20.6'W), 20 Sep 2007, D. and W. N. Mathis (1♀; USNM); Assateague Island, wildlife loop (37°54.6'N, 75°21.1'W), 20 Sep 2007, D. and W. N. Mathis (1♂; USNM).

Neotropical. BAHAMAS. Andros: Fresh Creek (24°44'N, 77°47'W), 23 Apr 1953, E. B. Hayden (1♀; AMNH). Grand Bahamas Island: West End (26°41'N, 78°58'W), 12 May 1953, E. B. Hayden, L. Giovannoli, G. B. Rabb (1♀; AMNH). Rum Cay: near Port Nelson (23°39.6'N, 74°49.8'W), 16 Mar 1953, E. B. Hayden, L. Giovannoli (2♀; AMNH).

BELIZE. Stann Creek: Bread and Butter Cay (16°45'N, 88°09'W), Mar 1988, W. N. Mathis (1♀; USNM); Hopkins (16°52'N, 88°17'W), 3 Apr 1993, W. N. Mathis (2♂, 1♀; USNM); Man of War Cay (17°13'N, 87°54'W), Nov 1987, W. N. and D. Mathis (1♀; USNM); Round Cay (near Coco Plum Cay; 16°52'N, 88°07'W), Mar 1988, W. N. Mathis (1♂, 1♀; USNM); Stewart Cay (16°46'N, 88°09'W), 9 Nov 1987, W. N. Mathis (1♂, 1♀; USNM); Twin Cays (Aanderaa Flats, dock area, east shore of East Island, mud flat near Lair Channel, south end of West Island, West Bay; 16°49.9'N, 88°06.1'W), Mar-Nov 1987, 1988, W. N. and D. Mathis (35♂, 29♀; USNM); Wee Wee Cay (16°45.9'N, 88°08.6'W), Mar-Nov 1987, 1988, W. N. and D. Mathis (2♂, 1♀; USNM).

CUBA. Havana: Playa Jibacoa (23°08.9'N, 81°51'W), 26 Apr 1983, W. N. Mathis (2♀; USNM); Puerto Escondido (23°08.7'N, 81°42.5'W), 26 Apr 1983, W. N. Mathis (1♀; USNM)). Sancti Spiritus: La Boca (4 km S; 21°45.9'N, 80°01.5'W), 12 Dec 1994, W. N. Mathis (3♂, 6♀; USNM).

DOMINICAN REPUBLIC. Azua: Puerto Viejo (18°20.9'N, 70°50.4'W), 14 May 1995, W. N. Mathis (8♂, 4♀; USNM). Barahona: Barahona (18°12'N, 71°5.3'W), 20 May 1998, D. and W. N. Mathis (7♂, 4♀; USNM). La Altagracía: Bayahibe (18°22.3'N, 68°50.4'W), 13 May 1994, W. N. Mathis (3♂, 5♀; USNM). La Romana:Isla Saona, Catuano (18°11.7'N, 68°46.8'W), 13 May 1995, W. N. Mathis (4♂, 2♀; USNM); Isla Saona, Mano Juan (18°08.1'N, 68°44.5'W), 13 May 1995, W. N. Mathis (11♂, 6♀; USNM). Monte Cristi: Monte Cristi (beach; 19°51.5'N, 71°39.5'W), 18 May 1995, W. N. Mathis (2♂; USNM). Pedernales: Lago Oviedo (N shore; 17°47'N, 71°22.5'W), 15 May 1995, W. N. Mathis (1♂, 3♀; USNM).

GRAND CAYMAN. Airport (2 km E; 19°17.1'N, 81°21'W), 26 Apr 1994, W. N. Mathis (2♂; USNM); Bodden Town (1.6 km E; 19°17.5'N, 81°13.3'W), Meagre Bay Pond, 29 Apr 1993, W. N. Mathis (4♂, 5♀; USNM); Double Head (19°23.4'N, 81°22.3'W), 27 Apr 1994, D. and W. N. Mathis (2♂, 5♀; USNM); Frank Sound Road (19°18.9'N, 81°10.9'W), 28 Apr 1994, W. N. Mathis (2♂, 4♀; USNM); George Town Harbour (19°18'N, 81°22.9'W), 28-29 Apr 1994, W. N. Mathis (9♂, 2♀; USNM); Governor Gore Bird Sanctuary (19°16.7'N, 81°18.5'W), 25 Apr 1994, W. N. Mathis (6♂, 1♀; USNM); Heritage Beach (19°18'N, 81°9.8'W), 28 Apr 1994, W. N. Mathis (3♂, 1♀; USNM); Spotts (19°16.5'N, 81°19.1'W), 25 Apr 1994, W. N. Mathis (11♂, 9♀; USNM).

JAMAICA. Clarendon: Barnswell Beach (17°45.'N, 77°08.5'W), 13 May 1996, D. and W. N. Mathis, H. B. Williams (13♂, 1♀; USNM); Farquhars Beach (17°50.9'N, 77°22.8'W), 9 May 1996, D. and W. N. Mathis, H. B. Williams (9♂, 1♀; USNM); Jackson Bay (17°44.7'N, 77°12.6'W), 13 May 1996, D. and W. N. Mathis, H. B. Williams (5♂; USNM); Portland Cottage (1 km S; 17°45.8'N, 77°12.6'W), 13 May 1996, D. and W. N. Mathis, H. B. Williams (4♂, 1♀; USNM). Manchester: Alligator Pond (17°52.1'N, 77°33.9'W), 8 May 1996, D. and W. N. Mathis, H. B. Williams (1♂, 3♀; USNM). St. Andrew: Mavis Bank (1.7 km E; 18°02.4'N, 77°39.5'W; 575 m), Yallahs River, 21-22 Apr-1 May 2000, W. N. Mathis (2♂, 1♀; USNM); Mavis Bank (4.3 km SE; 18°01.4'N, 76°38.1'W; 480 m); Yallahs River, 22-23 Apr 2000, W. N. Mathis (1♂, 1♀; USNM). St. Elizabeth: Black River (18°01.4'N, 77°51.1'W), 11 May 1996, D. and W. N. Mathis, H. B. Williams (5♂, 4♀; USNM); Salt Pond, Parottee Beach (17°58.1'N, 77°50.2'W), 19 Apr 2000, W. N. Mathis (7♂, 3♀; USNM); Ys Falls (18°09.3'N, 77°49.5'W), 17-18 Apr 2000, W. N. Mathis (1♀; USNM). Westmoreland: Negril (S beach; 18°17.7'N, 78°21.4'W), 11 May 1996, D. and W. N. Mathis, H. B. Williams (1♀; USNM).

PUERTO RICO. Playa de Guayanilla (18°0.4'N, 66°46.1'W), 19 Sep 1995, D. and W. N. Mathis (1♀; USNM); Punta Jacinto (near Guanica; 17°57'N, 66°52.6'W), 20 Sep 1995, D. and W. N. Mathis (1♂, 1♀; USNM).

Distribution

(Fig. 37). Nearctic: United States (Delaware, Florida, Mississippi, North Carolina, Texas, Virginia). Neotropical: Bahamas, Belize, West Indies (Cuba, Dominican Republic, Grand Cayman, Jamaica, Puerto Rico).

Natural history.

All specimens that we have examined are from localities that are associated with marine or at least brackish-water shorelines, indicating a tolerance and perhaps an affinity for these habitats.

Remarks.

Specimens of this species are usually relatively large and robust, especially the abdominal tergites. Unlike most congeners, there is some asymmetry in some structures of the male terminalia (similar to Polytrichophora flavella ; Figs 32, 35). From similar congeners, this species is distinguished by the shortened apical arms (apparently secondarily shortened) of the H-shaped hypandrium.