Polytrichophora orbitalis (Loew)

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 : 54-58

Polytrichophora orbitalis (Loew) Figs 9498

Discocerina orbitalis Loew 1861: 354.

Polytrichophora orbitalis . Cresson 1924: 161 [generic combination]; 1942: 114 [review of Nearctic fauna]. Wirth 1965: 740 [Nearctic catalog]. Mathis and Zatwarnicki 1995: 185-186 [world catalog]. Zatwarnicki and Mathis 2001: 49 [figs. ♂ terminalia].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.40-2.10 mm.

Head: Frons largely dull to faintly subshiny, brown with moderate investment of gray to yellowish gray microtomentum, anterior margin with some orange coloration; fronto-orbits narrow, gray to whitish gray. Antenna mostly yellow; basal flagellomere tannish yellow apicodorsally; arista with 5 dorsal rays. Face at narrowest point about equal to combined length of pedicel and basal flagellomere; face more densely microtomentose than frons, microtomentum with faintly shiny, mostly gray to whitish gray; parafacial and gena becoming slightly more whitish to silvery white than face; parafacial becoming wider ventrally with moderate ventral dilation; gena moderately high, height less than combined length of pedicel and basal flagellomere; gena-to-eye ratio 0.11-0.13.

Thorax: Mesonotum mostly dull to faintly subshiny, moderately densely microtomentose, mostly tan to brown, becoming gray laterally and anteriorly; pleural area mostly gray. Anterior margin of wing lacking spine-like setae; costal vein ratio 0.81 -0.95; M vein ratio 0.45-0.47. Legs, including most of coxae, yellow; forefemur lacking a row of 9-10 short, stout setulae along apical half of anteroventral surface; forefemur with a row of 4-5, of moderately well-developed, evenly spaced posteroventral setae on apical half, each seta less than width of femur; tibiae mostly gray, only apices yellowish; basal tarsomeres yellow, apical 1-2 becoming slightly darker, mostly tannish yellow.

Abdomen: Tergites dull to subshiny, gray to blackish brown; tergite 5 of male pointed apically, lacking row of 6-10, distinctly larger setae along extreme posterior margin with posterodorsal orientation. Male terminalia (Figs 94-97): Epandrium in posterior view (Fig. 94) generally elliptical, more or less uniformly setulose, dorsal margin rounded, both ventral extensions pointed, narrowly connected dorsally, in lateral view (Fig. 95) with ventral apex acutely pointed, cercus large, conspicuous; aedeagus tubular, tapered toward apex in lateral view to acute, partially recurved point, in ventral view (Fig. 96) narrowly elongate with lateral margins sinuous; phallapodeme in lateral view (Fig. 97) roughly triangular with extended keel truncate apically, in ventral view (Fig. 96) clavate with basal margin bluntly rounded; gonite in lateral view (Fig. 97) narrowly elongate, sinuous, in ventral view (Fig. 96) conspicuously arched, narrow, parallel sided; hypandrium in lateral view (Fig. 97) elongate, with lateral, irregular extension, in ventral view (Fig. 96) more or less broadly triangular, pointed anteriorly, posterior margin as 2 lateral projections, lateral one pointed, medial one wider and truncate apically.

Type material.

The lectotype female (not a male as Loew stated in the original description), designated herein, is labeled "[United States. District of Columbia] Loew Coll./orbitalis [handwritten]/Type 11147 [red, number handwritten]/Polytrichophora orbitalis (Lw.) det WWirth '[19]61 [species name handwritten, black submarginal border]/LECTOTYPE Discocerina orbitalis Loew ♀ By W. N.Mathis 1990 [species name and designator handwritten, black submarginal border]." The lectotype is double mounted (pin in a rectangular cork base), is in fair condition (pinned through base of abdomen, small amounts of verdigris, especially beneath the specimen), and is deposited in the MCZ (11147).

Type locality.

United States. District of Columbia: Washington (38°49.8'N, 77°00.6'W).

Other specimens examined.

Nearctic. CANADA. QUEBEC. Lac Meech (45°32.6'N, 73°54.2'W), 6 Jun 1960, W. W. Wirth (1♂; USNM).

UNITED STATES. CONNECTICUT. Canaan: Falls Village (41°57.4'N, 73°21.8'W), 29 Aug 1962, A. Stone (1♀; USNM). Fairfield: Putnam Park (41°02'N, 73°36.7'W), 22 Jul 1939, A. L. Melander (1♂; USNM). Windham: Eastford (41°53.6'N, 72°05.8'W), 25 Aug 1954, A. H. Sturtevant (1♂, 3♀; USNM).

DISTRICT OF COLUMBIA. Theodore Roosevelt Island (38°53.7'N, 77°03.7'W), 14 May 1977, W. N. Mathis (1♂; USNM); Washington (38°49.8'N, 77°00.6'W), D. L. Coquillett (1♂, 1♀; USNM).

MAINE. Waldo: Belfast (44°25.6'N, 69°0.4'W), 16-20 Sep 1946, C. W. Sabrosky (1♀; USNM).

MARYLAND. Anne Arundel: Edgewater (6 km S; 38°53'N, 76°33'W; Smithsonian Environmental Research Center), 4 Aug 1994, W. N. Mathis (4♂, 1♀; USNM). Carroll: Eldersburg (39°24.2'N, 76°57'W), 2 Jun 1985, J. E. Lowry, W. E. Steiner (1♀; USNM). Frederick: Point of Rocks (7.6 km W, 1.6 km N; 39°16.6'N, 77°31.9'W), 11 Jul 1982, G. F. and J. F. Hevel (1♂; USNM). Garrett: Broadford Lake (39°24.7'N, 79°22.4'W; 750 m), 20 Jun 2007, D. and W. N. Mathis (1♂, 1♀; USNM); Cranesville Swamp (39°31.9'N, 79°29.1'W; 775 m), 24 Aug 2006, D. and W. N. Mathis (1♂; USNM); Savage River (39°30.1'N, 79°06.9'W; 400 m), 23 Aug 2006, D. and W. N. Mathis (8♂, 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 (2♂; USNM). Montgomery: Cabin John (38°58.5'N, 77°09.5'W), 25 Jul 1972, G. C. Steyskal (1♂; USNM); Clarksburg, Little Bennett Regional Park (39°16'N, 77°16.8'W), 21 Sep 1990, M. J. and R. Molineaux, W. E. Steiner (2♂; USNM); Glen Echo (38°58.1'N, 77°08.4'W), 22 Aug 1922, W. L. McAtee (1♂; USNM); McKee-Beshers (39°05'N, 77°24.3'W), 7 Mar 2005, D. and W. N. Mathis (1♂, 1♀; USNM); Wheaton (39°02.3'N, 77°03.3'W), 26 Jul 1979, A. Freidberg (1♂; USNM). Prince George'S: Bladensburg (38°56.4'N, 76°56'W), 23 Sep 1915, R. C. Shannon (1♂; ANSP); Patuxent Wildlife Research Center (39°03'N, 76°48.2'W), 9 Jun 1967, W. W. Wirth (4♂, 3♀; USNM).

MASSACHUSETTS. Barnstable: Waquoit (41°35.4'N, 70°31.3'W), 16 Jul 1939, A. H. Sturtevant (1♂; USNM); Woods Hole (42°32.1'N, 70°39.6'W), 4 Sep 1950, A. H. Sturtevant (1♂; USNM).

MICHIGAN. Midland: Midland (43°36.9'N, 84°14.8'W), 28 Aug 1943, R. R. Dreisbach (1♂; USNM). Wayne: Detroit (42°21'N, 83°02.5'W), 2 May– 1 Jul 1938, 1944, G. C. Steyskal (4♀; ANSP, USNM).

NEW HAMPSHIRE. Grafton: Franconia Notch (44°08.5'N, 71°41.3'W), 8 Jul 1931, J. M. Aldrich (1♂; USNM).

NEW YORK. Cattaraugus: Allegany State Park, Salamanca (42°06.4'N, 78°45.8'W), 28 May-3 Jun 1963, W. W. Wirth (1♂; USNM). Richmond: South Beach, Staten Island (40°35.4'N, 74°05.5'W), 7 Oct 1916, A. H. Sturtevant (1♀; USNM). Rockland: Nyack (W; 41°05.4'N, 73°55.1'W), 11 Jun 1939, A. L. Melander (1♀; ANSP, USNM). Suffolk: Cold Spring Harbor, Long Island (40°52.3'N, 73°27.4'W), Aug, A. L. Melander (1♂, 1♀; ANSP, USNM). Sullivan: Beaverkill (41°58.9'N, 74°50.1'W), 10 Aug 1909, E. T. Cresson, Jr. (1♀; ANSP). Wyoming: Letchworth State Park (42°38.5'N, 77°58.9'W), 13 Jun 1963, W. W. Wirth (3♂, 1♀; USNM).

OHIO. Ashtabula: Pymatuning Lake State Park (41°39.4'N, 80°27.7'W), 13 Sep 1976, B. A. Steinly (2♂, 2♀; USNM). Highland: Rocky Fork State Park (39°10.7'N, 83°31'W), 17 Jul 1974, J. Regensberg (1♂; USNM). Loraine: Beaver Creek near Amherst (41°24.2'N, 82°14'W), 22 Aug 1977, B. A. Steinly (23♂, 25♀; USNM). Lawrence: Vesuvius Lake (38°34.6'N, 82°37.5'W), 23 Aug 1974, J. Regensberg (6♂, 2♀; USNM). Meigs: Forked Run (39°03.9'N, 81°46.3'W), 27 Aug 1974, J. Regensberg (1♂, 1♀; USNM). Mercer: Grand Lake, St. Marys near Montezuma (40°29.6'N, 84°33'W), 26 May 1977 B. A. Steinly (2♂, 2♀; USNM). Morgan: Oregonia (39°04'N, 84°13.2'W), 14 Jul 1974, J. Regensberg (2♂, 5♀; USNM).

PENNSYLVANIA. Allegheny: Jacks Run, Allegheny, 14 Jun 1908 (1♂; ANSP). Delaware: Swarthmore (39°54.1'N, 75°21.1'W), 19 Jun-16 Aug 1908, 1920, E. T. Cresson, Jr. (11♂, 9♀; ANSP). Erie: Presque Isle State Park, Thompson'S Bay (42°08.3'N, 80°07'W), 6 May 1977, B. A. Steinly (1♂, 1♀; USNM).Montgomery: Lansdale (40°14.5'N, 75°17.1'W), 12 Jul 1908 (1♀; ANSP); Narberth (3.2 km N; 40°10.5'N, 75°15.6'W), 9 Sep 1915, E. T. Cresson, Jr. (1♂; ANSP).

VIRGINIA. Accomack: Assateague Island, near Refuge headquarters (37°54.5'N, 75°21.6'W), 15 Jun– 3 Oct 2005, 2007, D. and W. N. Mathis (13♂, 4♀; USNM). Arlington: Barcroft Park, 4-Mile Run (38°50.8'N, 77°06.1'W), 9 Oct 2006, H. B. Williams (1♂; USNM). Chesterfield: Pocahontas State Park (37°23.1'N, 77°32.4'W), 11 May 2002, D. and W. N. Mathis (1♂; USNM). Culpeper: Lake Pelham (38°27.8'N, 78°02.7'W), 28 Apr 2006, D. and W. N. Mathis (9♂, 3♀; USNM). Fairfax: Dead Run (mouth; 38°58'N, 77°10.4'W), 24 Apr 2006, D. and W. N. Mathis (9♂, 10♀; USNM); Great Falls (Clay Pond; 39°00.1'N, 77°15.4'W), 23 Apr– 13 Sep 2006, 2007, D. and W. N. Mathis, H. B. Williams, T. Zatwarnicki (51♂, 18♀; USNM); Great Falls (quarry; 38°59.1'N, 77°14.8'W; 50 m), 23 Apr 2007, D. and W. N. Mathis (1♂, 1♀; USNM); Great Falls (swamp trail; 38°59.4'N, 77°15.2'W), 12 May 2006, D. and W. N. Mathis (11♂, 2♀; USNM); Great Falls (Potomac River; 39°0.2'N, 77°15.2'W), 13 Sep 2007, D. and W. N. Mathis, H. B. Williams (1♂; USNM); Great Falls (Patowmack Canal; 39°00.1'N, 77°15.2'W), 27 Jun– 29 Aug 2006, 2007, D. and W. N. Mathis (21♂, 7♀; USNM); Great Falls (quarry; 38°59.1'N, 77°14.8'W; 50 m), 13 Jun 2007, D. and W. N. Mathis (4♂; USNM); Turkey Run (38°57.8'N, 77°09.4'W), 4 May 2006, D. and W. N. Mathis (6♂, 2♀; USNM); Turkey Run (mouth; 38°57.9'N, 77°09.4'W), 20 Apr-17 Sep 2006, 2007, D. and W. N. Mathis, H. B. Williams, T. Zatwarnicki (85♂, 15♀; USNM). Grayson: Galax (15 km S; Chestnut Creek; 36°34.9'N, 80°53.5'W), 28 Jun 1986, W. E. Steiner (1♂, 1♀; USNM). Henry: Martinsville Reservoir (36°44.7'N, 79°52.2'W), 17 May 2005, D. and W. N. Mathis (1♂; USNM). Madison: Criglersville (1.6 km W; 38°28.4'N, 78°19.9'W; 185 m; Robinson River), 19 May– 1 Jul 2005, D. and W. N. Mathis (1♂, 2♀; USNM). Middlesex: Dragon Run (37°38'N, 76°41.7'W), 17 Sep 2004, D. and W. N. Mathis (10♂, 3♀; USNM). Patrick: Meadows of Dan (36°44.2'N, 80°22.9'W), 18 May 2005, D. and W. N. Mathis (3♂, 5♀; USNM). Prince William: Prince William Forest Park: (38°34'N, 77°22'W; Carter Pond), 13 Aug 1993, D. and W. N. Mathis (2♂, 1♀; USNM); Prince William Forest Park, South Quantico Creek (shoreline, 38°34'N, 77°22'W), 10 Jul-13 Aug 1993, D. and W. N. Mathis (18♂, 21♀; USNM). Roanoke: Salem (Roanoke River; 37°16.1'N, 80°02.2'W; 300 m), 23 Sep 2007, D. and W. N. Mathis (4♂, 1♀; USNM). Spotsylvania: Rappahannock River (38°18.8'N, 77°32.5'W), 15 Apr-14 Aug 2006, 2007, D. and W. N. Mathis (11♂, 6♀; USNM). Stafford: Aquia Creek (38°29.1'N, 77°23.8'W), 6 Jun 2005, D. and W. N. Mathis (1♀; USNM); Aquia Harbour (38°27.9'N, 77°23.3'W), 15 May– 21 Jul 1988, 2000, D. and W. N. Mathis (29♂, 7♀; USNM); Aquia Harbour, Lions Park (38°27'N, 77°23.3'W), 10 Apr-4 Nov 2003, 2005, 2006, 2007, D. and W. N. Mathis (32♂, 7♀; USNM); Curtis Park Lake (38°26'N, 77°33.3'W), 2 Jul 2005, D. Mathis (1♀; USNM); Falmouth (38°19.2'N, 77°28.1'W; Rappahannock River; 9 m), 30 Jun 2007, D. and W. N. Mathis (3♂; USNM); Lunga Reservoir (38°32'N, 77°27.4'W), 27 Apr 2006, D. and W. N. Mathis (1♀; USNM). Westmoreland: Westmoreland State Park (38°09.7'N, 76°51.9'W), 16 Sep 1994, D. and W. N. Mathis (3♂, 2♀; USNM). Independent Cities: Fredericksburg (Rappahannock River; 38°18.3'N, 77°27.5'W), 14 Apr 2006, D. and W. N. Mathis (1♂, 5♀; USNM); Norfolk (36°50.8'N, 76°17.1'W), 14 Aug 1969, G. C. Steyskal (1♂; USNM).

WEST VIRGINIA. Hardy: Baker (39°02.5'N, 78°44.9'W; 405 m), 12 Jul 2007, D. and W. N. Mathis (2♂, 1♀; USNM); Mathias (38°52.6'N, 78°52'W; 465 m), 13 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 (5♂; USNM). McDowell: Roderfield (37°26.7'N, 81°42.2'W; 335 m), 25 Sep 2007, D. and W. N. Mathis (1♂, 1♀; USNM). Mercer: Ceres (Kee Reservoir; 37°18.4'N, 81°10.4'W; 757 m), 24 Sep 2007, D. and W. N. Mathis (1♂; USNM). Summers: Bluestone State Park (37°36.7'N, 80°56.1'W; 440 m), 26 Sep 2007, D. and W. N. Mathis (1♂; USNM).

Distribution

(Fig. 98). Nearctic: Canada (Quebec), United States (Connecticut, District of Columbia, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New York, Ohio, Pennsylvania, Virginia, West Virginia).

Remarks.

This is the nominate species of the orbitalis group and is distinguished by characters of the male terminalia as follows: Area between anterior arms of the hypandrium membranous; the ventral margin of the epandrium is abruptly tapered to apex; and the hypandrium is small and weakly sclerotized (Figs 94-97).