Hydrochasma leucoproctum (Loew)

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2013, A revision of the shore-fly genus Hydrochasma Hendel (Diptera, Ephydridae), ZooKeys 363, pp. 1-161 : 92-99

publication ID

https://dx.doi.org/10.3897/zookeys.363.6482

publication LSID

lsid:zoobank.org:pub:780695A9-CB2E-4FEC-A056-0BA6F456185E

persistent identifier

https://treatment.plazi.org/id/1E68FC59-7A51-AC57-1DED-1377701A6571

treatment provided by

ZooKeys by Pensoft

scientific name

Hydrochasma leucoproctum (Loew)
status

 

31. Hydrochasma leucoproctum (Loew) Figs 172-179, 185

Discocerina leucoprocta Loew, 1861: 355 [United States. “Maryland”; HT ♀, MCZ (11148)]. Aldrich 1905: 626 [Nearctic catalog]. Jones 1906: 178 [catalog]. Deonier 1964: 122 [key to species of Iowa]; 1965: 501 [habitats and abundance in Iowa].

Hydrochasma leucoproctum . Cresson 1942: 113 [generic combination, as Hydrochasma leucostoma ]; 1946: 141 [list, Guatemala, Panama, Bolivia]. Wirth and Stone 1956: 468 [key, California]. Wirth 1965: 739 [Nearctic catalog]; 1968: 8 [Neotropical catalog]. Mathis and Zatwarnicki 1995: 183 [world catalog]. Mathis and Mathis 2008: 180-181 [shore flies of Plummers Island].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.50-1.95 mm. Head: Antenna mostly yellowish; parafacial silvery white, contrasted with mostly yellowish face; face yellowish, extreme lateral margins brownish black; facial coloration at most only slightly distinct from parafacial (Figs 172-174). Gena moderately high, height usually slightly higher than length of basal flagellomere, gena-to-eye ratio 0.19-0.21. Thorax: Wing hyaline; with costal vein ratio 0.63-0.65; M vein ratio 0.46-0.50. Forecoxa mostly gray to blackish gray, at most only slightly yellowish; hindtibia lacking a ventral, spur-like seta near apex. Abdomen: Tergites 1-4 with dorsum entirely brownish black, with lateral margin sharply demarcated from silvery gray to gray portion, lacking grayish wedges laterally on tergites 2-4; tergite 5 light gray to silvery gray (Fig. 185), similar to coloration along lateral margins of preceding tergites but with posterior margin blackish brown to slate black, similar to coloration of medial area on tergites 1-4; medial coloration on tergites 1-4 wide, occupying most of dorsum, dark, grayish to slate black. Male terminalia (Figs 175-178): Combined structures generally elongate, in posterior view height more than twice width; epandrium with dorsal arch above cerci thinly developed, in posterior view (Fig. 175) as an inverted U on dorsal half, dorsal portion setulose, middle portion with lateral margins angled medially, generally lacking setulae, ventroapical portion with height about equal to that of cerci, parallel sided, partially bifurcate medially, broadly rounded apically, in lateral view (Fig. 176) with ventral 2/3 narrow, almost parallel sided with subapical, slightly narrowing, apical portion oriented anteriorly slightly, apex rounded; cerci short, height not quite twice width (Fig. 175), tenuously attached lateroventrally with epandrium; aedeagus in lateral view (Fig. 178) elongate, over 5 × longer than width, tubular, slightly arched, with apical portion somewhat rectangular, in ventral view (Fig. 177) essentially parallel sided, apex pointed; phallapodeme in lateral view (Fig. 178) narrow, elongate, unevenly C-shaped with more curvature toward attachment with hypandrium, keel short and narrow, extended margin irregularly serrate, in ventral view (Fig. 177) narrowly Y-shaped with arms short and right angled; gonite in lateral view (Fig. 178) narrow, elongate, bar-like, in ventral view (Fig. 177) very shallowly angled at midlength; hypandrium in lateral view (Fig. 178) elongate, shallow, anterior 2/3 parallel sided, in ventral view (Fig. 177) with posterior half divergently U-shaped, anterior portion narrower, plate, rounded around anterior margin.

Type material.

The holotype female is labeled "[United States.] Md. [Maryland]/Loew Coll./leucoprocta m[ihi]. [handwritten]/Type 11148 [red; number handwritten]/Hydrochasma leucoproctum (Lw.) WWirth '61 [1961] [species name handwritten]/HOLOTYPE Discocerina leucoprocta Loew ♀ [pink; handwritten]." The holotype is double mounted (small pin in a rectangular block of pith), is in good condition (right basal flagellomere missing), and is deposited in the MCZ.

Type locality.

United States. “Maryland.”

Other specimens examined.

Nearctic. UNITED STATES. DELAWARE. Kent: Woodland Beach (39°19.9'N, 75°28.3'W; beach), 18 May 2006, D. and W. N. Mathis (3♂; USNM).

DISTRICT OF COLUMBIA. Chain Bridge (38°55.8'N, 77°6.9'W), 26 May-2 Sep 1916, 1922, W. L. McAtee (2♂, 1♀; USNM); Rock Creek, Boundary Bridge (38°59.2'N, 77°03.2'W), 18 May 2007, D. and W. N. Mathis (2♂; NPSRC, USNM); Washington (38°49.8'N, 77°00.6'W), D. W. Coquillett (1♂; USNM).

FLORIDA. Marion: Salt Springs (29°21.1'N, 81°44.1'W), 14 Apr 1989, D. and W. N. Mathis (7♂, 10♀; USNM); Silver Springs (29°13'N, 82°03.5'W), 2 Apr 1932, A. L. Melander (1♂; ANSP). Pinellas: St. Petersburg (27°44.3'N, 82°40.8'W), 19 Feb 1924, E. T. Cresson, Jr. (1♀; ANSP).

GEORGIA. Tifton: Tifton (31°27'N, 83°30.5'W), 6 Sep-Oct 1896 (8♀; ANSP).

ILLINOIS. Adams: Quincy (Mississippi River; 39°57.3'N, 91°25.1'W), 3 Sep 1995, J. F. Edmiston (3♂; USNM).

INDIANA. Tippecanoe: Lafayette (40°25'N, 86°52.5'W), 24 May-5 Sep 1916, E. W. Stafford (2♀; ANSP).

KANSAS. Riley: Manhattan (39°11'N, 96°34.3'W), 9 Jun 1934, C. W. Sabrosky (1♀; ANSP).

MARYLAND. Anne Arundel: Edgewater (6 km S; 38°53'N, 76°33'W; Smithsonian Environmental Research Center), 6 Jul 1976, J. H. Falk (8♂, 4♀; USNM). Carroll: Eldersburg (39°24.2'N, 76°57'W), 2 Jun 1985, J. E. Lowry, W. E. Steiner (1♂; USNM). Garrett: Savage River (39°30.1'N, 79°06.9'W; 400 m), 23 Aug 2006, D. and W. N. Mathis (1♂, 1♀; USNM); Savage River Reservoir (near Floyd; 39°30.7'N, 79°09.3'W; 420 m), 23 Aug 2006, D. and W. N. Mathis (4♂; USNM). Montgomery: Bethesda (38°58.8'N, 77°06'W), 24 May 1969, G. C. Steyskal (1♀; USNM); Plummers Island (38°58.2'N, 77°10.6'W), 30 May-4 Jul 1907, 1914, W. L. McAtee (2♀; USNM). Prince George’s: 4 Jul 1954, C. W. Sabrosky (1♀; USNM); Patuxent Wildlife Research Center (39°03'N, 76°48.2'W), 9 Jun 1967, W. W. Wirth (2♂, 3♀; USNM).

MICHIGAN. Bay: Bay City (43°35.7'N, 83°53.3'W), 16 Aug 1936, R. R. Dreisbach (2♂, 1♀; ANSP). Kalamazoo: Kalamazoo (42°17.5'N, 85°35'W), 10 May 1936, C. W. Sabrosky (1♀; ANSP). Monroe: Monroe (41°55'N, 83°23.9'W), 2 Jul 1939, G. C. Steyskal (1♂; ANSP).

NEW JERSEY. Atlantic: Absecon (39°24.9'N, 74°29.6'W), 26 Sep 2003, D. and W. N. Mathis (3♂; USNM). Cape May: Wildwood (38°59.5'N, 74°48.9'W), 18 Jul 1908 (1♂; ANSP). Ocean: Manahawkin (39°41.9'N, 74°15.5'W), 19 Aug 2004, D. and W. N. Mathis (1♀; USNM); Tuckerton (39°36.2'N, 74°20.8'W), 17-18 Jun-19 Aug 2004, W. & D. Mathis (8♂, 5♀; USNM); Tuckerton (16 km N; 39°53.3'N, 74°22.8'W), 26 Sep 2003, D. and W. N. Mathis (1♂; USNM).

NEW MEXICO. Grant: Bill Evans Lake (32°52.1'N, 108°34.5'W; 1416 m), 14 Aug 2007, D. and W. N. Mathis (7♂, 1♀; USNM).

OHIO. Highland: Rocky Ford State Park (39°10.9'N, 83°24.9'W), 17 Jul 1974, J. Regensberg (1♀; USNM). Lawrence: Vesuvius Lake (38°34.6'N, 82°37.5'W), 23 Aug 1974, J. Regensberg (1♀; USNM). Morgan: Burr Oak State Park (39°33.3'N, 82°02.8'W), 26 Aug 1974, J. Regensberg (1♂; USNM).

PENNSYLVANIA. Allegheny: Jacks Run (40°20.8'N, 79°47.5'W), 14 Jun 1908 (1♂; ANSP). Delaware: Swathmore (39°54.1'N, 75°21.1'W), 26 Jun-4 Jul 1908, 1909, 1910, E. T. Cresson, Jr. (26♂, 12♀; ANSP). Montgomery: Lansdale (40°14.5'N, 75°17'W), 12 Jul 1908 (2♀; ANSP); Narberth (3.2 km N; 40°0.8'N, 75°15.6'W), 9 Sep 1915, E. T. Cresson, Jr. (2♂, 2♀; ANSP).

TEXAS. Augustine: Rayburn Park (31°04'N, 94°05'W), 15 May 1993, D. and W. N. Mathis (1♂, 2♀; USNM). Jasper: Boykin Springs (31°05'N, 94°17'W), 15 May 1993, D. and W. N. Mathis (1♂; USNM).

VIRGINIA. Accomack: Assateague Island, near Refuge headquarters (37°54.5'N, 75°21.6'W), 19 Sep-3 Oct 2005, 2007, D. and W. N. Mathis (10♂; USNM). Arlington: 4-Mile Run (38°50.4'N, 77°02.7'W), 11 Sep 1977, W. N. Mathis (1♀; USNM). Chesapeake: Lake Drummond (36°36.2'N, 76°28.1'W), 29 June 1939, A. L. Melander (1♂; ANSP). Chesterfield: Pocahontas State Park (37°23.1'N, 77°32.4'W), 11 May 2002, D. and W. N. Mathis (6♂, 1♀; USNM). Fairfax: Dead Run (mouth; 38°58'N, 77°10.4'W), 24 Apr 2006, D. and W. N. Mathis (2♂; USNM); Dead Run (swamp; 38°57.8'N, 77°10.3'W), 4 May 2006, D. and W. N. Mathis (2♂, 1♀; USNM); Great Falls (Clay Pond; 39°00.1'N, 77°15.4'W), 12 May-17 Aug 2006, 2007, D. and W. N. Mathis, T. Zatwarnicki (7♂, 3♀; USNM); Great Falls (Patowmack Canal; 39°00.1'N, 77°15.2'W), 20 Jun-3 Oct 2006, 2007, D. and W. N. Mathis (14♂, 3♀; USNM); Great Falls (Potomac River; 39°0.2'N, 77°15.2'W), 13 Sep-4 Oct 2007, D. and W. N. Mathis, H. B. Williams (9♂, 1♀; USNM); Great Falls (quarry; 38°59.1'N, 77°14.8'W; 50 m), 13 Jun 2007, D. and W. N. Mathis (5♂, 1♀; USNM); Great Falls (swamp trail; 38°59.4'N, 77°15.2'W), 12 May 2006, D. and W. N. Mathis (1♂; USNM); Turkey Run (38°57.8'N, 77°09.4'W), 4 May-7 Sep 2006, D. and W. N. Mathis (2♂; USNM); Turkey Run (mouth; 38°57.9'N, 77°09.4'W), 22 May-17 Sep 2006, 2007, 2008, D. and W. N. Mathis, H. B. Williams, T. Zatwarnicki (43♂, 13♀; USNM). Essex: Tappahannock (37°55.8'N, 76°51.4'W; Rappahannock River), 18 Sep 2004, D. and W. N. Mathis (1♂, 1♀; USNM). Henry: Martinsville Reservoir (36°44.7'N, 79°52.2'W), 17 May 2005, D. and W. N. Mathis (4♂, 2♀; USNM); Martinsville, Smith River (36°39.9'N, 79°53'W; 225 m), 18 May 2005, D. and W. N. Mathis (2♂, 5♀; USNM). Patrick: Meadows of Dan (36°44.2'N, 80°22.9'W), 18 May 2005, D. and W. N. Mathis (1♂, 2♀; USNM); Woolwine (36°47.4'N, 80°16.7'W; 300 m), 17 May 2005, D. and W. N. Mathis (4♂; USNM). Prince William: Prince William Forest Park, South Quantico Creek (38°34'N, 77°22'W), 10 Jul-13 Aug 1993, D. and W. N. Mathis (4♂, 1♀; USNM). Rappahannock: Hazel River (NW Culpeper; 38°33.8'N, 78°11.6'W, 171 m), 28 Jun-24 Jul 2008, D. and W. N. Mathis and T. Zatwarnicki (6♂; USNM). Roanoke: Salem (Roanoke River; 37°16.1'N, 80°02.2'W; 300 m), 23 Sep 2007, D. and W. N. Mathis (8♂; USNM). Spotsylvania: Rappahannock River (38°18.8'N, 77°32.5'W), 3 Jul-10 Oct 2006, 2007, D. and W. N. Mathis (14♂, 1♀; USNM). Stafford: Aquia Creek (38°29.1'N, 77°23.8'W), 6 Jun 2005, D. and W. N. Mathis (5♂, 3♀; USNM); Aquia Harbour (38°27.7'N, 77°23.3'W), 15 May-21 Jul 2000, D. and W. N. Mathis (2♂, 2♀; USNM); Aquia Harbour, Aquia Creek (38°27.8'N, 77°23.1'W), 2 Sep 2006, D. and W. N. Mathis (1♂, 1♀; USNM); Aquia Harbour, Lions Park (38°27'N, 77°23.3'W), 9 May-16 Nov 2003, 2004, 2005, 2006, 2007, 2008, D. and W. N. Mathis (166♂, 17♀; USNM); Aquia Harbour (3 km N Stafford; 38°27'N, 77°23.3'W), 8 Jun-6 Oct 1988, 2003, D. and W. N. Mathis (27♂, 9♀; USNM); Aquia Landing (38°23.2'N, 77°19'W), 5 Nov 2005, D. and W. N. Mathis (1♂; USNM); Falmouth (38°19.2'N, 77°28.1'W; Rappahannock River; 9 m), 18 Apr-30 Jun 2007, 2008, D. and W. N. Mathis (14♂, 3♀; USNM). Westmoreland: Popes Creek (G. Washington birthplace; 38°13.7'N, 76°54.6'W), 16 Sep 1994, W. N. Mathis (1♂; USNM); Westmoreland State Park (bank of Potomac River; 38°09.7'N, 76°51.9'W), 9 Jun-25 Aug 1988, 2004, D. and W. N. Mathis (12♂, 6♀; USNM). Independent City: Virginia Beach (Little Island; 36°41.6'N, 75°55.5'W), 18 Aug 2006, D. and W. N. Mathis (7♂; USNM).

WEST VIRGINIA. Hardy: Baker (39°02.5'N, 78°44.9'W; 405 m), 12 Jul 2007, D. and W. N. Mathis (1♂, 1♀; USNM); Trout Pond (38°57.4'N, 78°44.2'W; 595 m), 13 Jul 2007, D. and W. N. Mathis (2♂, 3♀; USNM). Morgan: Third Hill Mountain near Sleepy Creek (39°40.2'N, 78°05.1'W; 190 m), 30 Jul 1939, J. A. G. Rehn and J. W. H. Rehn (1♀; ANSP). Summers: Bluestone State Park (37°36.7'N, 80°56.1'W; 440 m), 26 Sep 2007, D. and W. N. Mathis (5♂; USNM); Hinton (37°41.8'N, 80 °53'W; New River; 427 m), 26 Sep 2007, D. and W. N. Mathis (7♂, 1♀; USNM). Wyoming: R. D. Bailey Lake (37°35.7'N, 81°46.8'W; 324 m), 25 Sep 2007, D. and W. N. Mathis (9♂, 1♀; USNM).

Neotropical. BELIZE. Stann Creek: Dangriga (16°58'N, 88°13'W), 3-4 Apr 1993, W. N. Mathis (2♀; USNM).

BRAZIL. Amazonsas: Manaus, INPA (03°05.9'S, 59°59.1'W; 60 m), 4 May 2010, D. and W. N. Mathis (1♂, 2♀; INPA, USNM); Reserva Ducke (02°55.8'S, 59°58.5'W; 40 m), 5 May 2010, D. and W. N. Mathis (1♀; INPA, USNM). Paraná: Bocaiúva do Sul (25°16.6'S, 48°58.5'W; 770 m), 16 Feb Jan 2010, D. and W. N. Mathis (1♂; DZUP, USNM); Curitiba, Universidade Federal do Paraná, Reserva Biológica (25°26.9'S, 49°14'W; 915 m), 9-11 Dec 2009, D. and W. N. Mathis (1♂, 2♀; DZUP, USNM); Morretes (25°28'S, 48°59.1'W), 29 Aug 2000, D. and W. N. Mathis (1♂; USNM).

COLOMBIA. Valle de Cauca: Sevilla (27 km W; 04°14.3'N, 76°01'W), 7 Mar 1955, E. S. Ross, E. I. Schlinger (1♂; USNM).

COSTA RICA. Alajuela: Alajuela (10°01'N, 84°13'W; 945 m), 15 Sep 1909, P. P. Calvert (6♂, 1♀; ANSP). Cartago: La Suiza (09°51.5'N, 83°37.5'W), 28 Jun 2001, W. N. Mathis (12♂; USNM). Limón: Cahuita (09°44.2'N, 82°50.4'W; beach), 28 Jun 2001, A. Freidberg (1♀; USNM); Guandoca, Manzanillo, Desembocadura, Laguna Guandoca (09°36.8'N, 82°40.9'W), 19-25 May 2004, D. Briceño (2♂; INBio); Parque Nacional Cahuita, Sector Puerto Vargas (09°44'N, 82°49'W; 1 m), 27-28 Jun 2001, J. D. Giterrez (4♂, 2♀; INBio); Westfalia (4 km S; 09°54.5'N, 82°59'W; beach), 27 Jun 2001, D. and W. N. Mathis (1♂; USNM). Puntarenas: Jacó (5 km E; 09°34.7'N, 84°35.6'W), 10 Jun 2003, D. and W. N. Mathis (2♂, 1♀; USNM); Montezuma (2 km S; 09°38.7'N, 85°04.4'W), 20 Jun 2001, D. and W. N. Mathis (1♂; USNM); Playa Jacó (09°36.5'N, 84°37.4'W; beach), 13 Jun 2003, D. and W. N. Mathis (1♂; USNM); Rincón (5 km S; 08°42.1'N, 83°30.8'W; 95 m), 10-11 Aug 2001, D. and W.N. Mathis (2♂; USNM); San Pedrillo (08°37.2'N, 83°44.1'W), 12-14 Aug 2001, D. and W.N. Mathis (8♂, 1♀; USNM). San José: Río S. Paraíso (09°33.8'N, 84°07.4'W; 350-400 m), 15-17 Feb 2003, W. N. Mathis (1♂; USNM).

ECUADOR. Orellana: Río Tiputini (0°38.2'S, 76°8.9'W), 12-26 Aug 1999, W. N. Mathis, A. Baptista, M. Kotrba (2♂; USNM).

GUYANA. Kumu River and Falls (25 km SE Lethem in Kanuku Mountains; 03°15.9'N, 59°43.6'W), 4-30 Apr 1994, 1995, W. N. Mathis (3♂, 4♀; USNM). Moco-Moco (30 km E Lethem in Kanuku Mountains; 03°18.2'N, 59°39.0'W), 3-29 Apr 1994, 1995, W. N. Mathis (4♂, 4♀; USNM).

HONDURAS. Cortés: Omoa (16°47.8'N, 87°58.4'W), 26 Sep 1995, D. and W. N. Mathis (5♂, 1♀; USNM); Puerto Cortés /Omoa (15°49'N, 87°56.2'W), 26 Sep 1995, D. and W. N. Mathis (1♂; USNM); San Pedro Sula (8 km S; 15°25.7'N, 88°01.4'W), 25-26 Sep 1995, D. and W. N. Mathis (1♂, 1♀; USNM).

MEXICO. Chiapas: Finca Prusia (33 km S Jaltenango; 15°49'N, 92°42'W), 10-12 May 1985, W. N. Mathis (1♀; USNM); Jaltenango (21 km S; 15°54'N, 92°40'W), 16 May 1985, W. N. Mathis (1♀; USNM). Michoacán: Uruapan (19°25'N, 102°03'W; 1600-1700 m), Aug 1975, N. L. H. Krauss (1♂; USNM). Morelos: Cuernavaca (18°56'N, 99°13.9'W), Apr 1965, N. L. H. Krauss (1♀; USNM). Veracruz-Llave: Ciudad Alemán (18°10.1'N, 96°06.2'W), 3 May 1985, W. N. Mathis (2♂, 2♀; USNM).

PANAMA. Panama: Tabernilla (09°08.9'N, 79°48.7'W), 6 Feb 1911, A. Busch (1♂, 1♀; ANSP).

PERU. Cuzco: Paucartambo, Atalaya ( Río Alto Madre de Dios; 12°53.1'S, 71°21.6'W; 600 m), 4 Sep 1988, W. N. Mathis (1♀; USNM). Madre de Dios: Río Manu, Erika (near Salvación; 12°50.7'S, 71°23.3'W; 550 m), 5-6 Sep 1988, W. N. Mathis (1♂; USNM).

VENEZUELA. Aragua: Ocumare de la Costa (2 km N; 10°28.5'N, 67°45.8'W), 31 Mar-2 Apr 1981, A. S. Menke, L. Hollenberg (1♂, 2♀; USNM). Trujillo: Sabana Grande (09°26.3'N, 70°46.2'W), 3 Jun 1976, A. S. Menke, D. Vincent (1♂; USNM).

West Indies. DOMINICAN REPUBLIC. La Vega: Jarabacoa (1-2 km S; 19°06.9'N, 70°37'W; 520 m), 8-21 May 1995, W. N. Mathis (2♀; USNM). Puerto Plata: Río Camu (14 km E Puerto Plata; 19°41.9'N, 70°37.4'W), 17 May 1995, W. N. Mathis (2♂; USNM).

GRENADA. St. Andrew: Balthazar (12°07.7'N, 61°39.3'W), 15-19 Sep 1996, 1997, W. N. Mathis (5♂, 2♀; USNM); Grand Étang (lake; 12°05.6'N, 61°41.7'W), 14 Sep 1997, W. N. Mathis (1♂; USNM). St. George: Beauséjour Bay (12°05.5'N, 61°44.9'W), 21 Sep 1996, W. N. Mathis (7♂, 4♀; USNM). St. John: Concord Valley (12°06.9'N, 61°43.9'W), 14 Sep 1996, W. N. Mathis (6♂, 1♀; USNM); Palmiste (12°08.7'N, 61°44.4'W), 21 Sep 1996, W. N. Mathis (2♂, 1♀; USNM).

PUERTO RICO. Vieques Island (18°08.8'N, 65°26.7'W), Feb 1899, A. Busck (1♀; misidentified paratype of Discocerina incisa ; USNM).

ST. LUCIA. Castries (5 km S; 13°59'N, 60°00'W), 16 Jun 1991, D. and W. N. Mathis (2♂; USNM); Dauphin Boguis (1.6 km S Marquis; 14°01'N, 60°55'W), 17 Jun 1991, D. and W. N. Mathis (4♂; USNM); Micoud (13°49'N, 60°54'W), 15 Jun 1991, D. and W. N. Mathis (7♂, 2♀; USNM). St. Patrick: Poyntzfield (12°10.5'N, 61°37.4'W), 20 Sep 1996, W. N. Mathis (1♀; USNM).

ST. VINCENT. Charlotte: Montreal (13°12'N, 61°11'W), 26 Mar-9 Jun 1989, 1991, A. Freidberg, D. and W. N. Mathis (1♀; USNM); Peruvian Vale (13°10.7'N, 61°08.7'W), 6-8 Sep 1997, W. N. Mathis (1♂; USNM); South Rivers (13°14.6'N, 61°09.3'W), 8 Sep 1997, W. N. Mathis (4♂; USNM); Spring (13°11.1'N, 61°08.5'W), 6 Sep 1997, W. N. Mathis (8♂; USNM); Yambou River (13°09.8'N, 61°08.7'W), 8-10 Sep 1997, W. N. Mathis (15♂, 1♀; USNM). St. Andrew: Buccament Bay (near beach; 13°11'N, 61°16'W), 25-28 Mar-8 Jun 1989, 1991, D. and W. N. Mathis (1♂, 1♀; USNM); Camden Park (13°10.2'N, 61°14.7'W), 4 Sep 1997, W. N. Mathis (12♂, 2♀; USNM); Layou (13°12'N, 61°17'W), 8 Jun 1991, D. and W. N. Mathis (10♂, 8♀; USNM). St. David: Richmond Beach, 28 Mar 1989, W. N. Mathis (3♂, 3♀; USNM). St. George: Kingston, Botanical Garden (13°9.7'N, 61°13.7'W), 25-27 Mar 1989, W. N. Mathis (2♂, 2♀; USNM); Yam bou Head, 27 Mar 1989, W. N. Mathis (3♂, 2♀; USNM). St. Patrick: Cumberland Bay (13°16'N, 61°16'W), 28 Mar-15 Sep 1989, 1991, 1997, A. Freidberg, D. and W. N. Mathis (27♂, 19♀; USNM); Cumberland River (3 km E Spring Village; 13°15'N, 61°14'W), 10 Jun 1991, D. and W. N. Mathis (20♂, 5♀; USNM); Hermitage (13°15'N, 61°12.9'W), 9 Sep 1997, W. N. Mathis (4♂; USNM); Palmiste Park (13°12.7'N, 61°14.9'W), 5 Sep 1997, W. N. Mathis (1♂; USNM); Wallilabou (beach; 13°15'N, 61°16'W), 27 Mar-8 Jun 1989, 1991, D. and W. N. Mathis (11♂, 8♀; USNM).

Distribution

(Fig. 179). Nearctic: United States (Delaware, District of Columbia, Florida, Georgia, Illinois, Indiana, Kansas, Maryland, Michigan, New Jersey, New Mexico, Ohio, Pennsylvania, Texas, Virginia, West Virginia). Neotropical: Belize (Stann Creek), Brazil (Amazonas, Paraná), Colombia (Valle de Cauca), Costa Rica (Cartago, Limón, Puntarenas, San José), Ecuador (Orellana), Guyana, Honduras, Mexico (Chiapas, Michoacán, Morelos, Veracruz-Llave), Panama (Panama), Peru (Cuzco, Madre de Dios), Venezuela (Aragua, Trujillo), West Indies (Dominican Republic, Grenada, Puerto Rico, St. Lucia, St. Vincent).

Remarks.

This is one of the more common species of the genus in eastern North America and is found from Michigan and Pennsylvania south into northern South America. In the Delmarva States, this is likewise a widespread species, occurring along the coastal plain, Piedmont, Blue Ridge, and Alleghany zones.

This species is distinguished from others of the leucoproctum group by the uniquely shaped epandrium, especially the ventral epandrial process, which is generally tapered until the apical portion that is parallel sided. In addition the hypandrium is H-shaped, having both anterior and posterior emarginations.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Ephydridae

Genus

Hydrochasma