Discocerina buccata (Cresson)

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2013, A revision of the shore-fly genus Hydrochasma Hendel (Diptera, Ephydridae), ZooKeys 363, pp. 1-161 : 105-109

Discocerina buccata (Cresson) Fig. 196-199

Hecamedoides buccata Cresson, 1930: 78.

Hydrochasma buccatum . Cresson 1942: 113 [generic combination]. Wirth 1965: 738 [Nearctic catalog]. Mathis and Zatwarnicki 1995: 182 [world catalog].

Discocerina buccata . Zatwarnicki and Mathis 2001: 22 [generic combination].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Generally densely microtomentose, whitish gray to blackish gray. Moderately small shore flies, body length 2.55-2.90 mm. Head: Frons moderately to densely microtomentose, whitish gray; anterior portion with some reddish orange coloration. Antenna largely black; basal flagellomere more brownish black with basal portion faintly yellowish orange; arista bearing 4-5 dorsal rays. Dorsal facial seta arising from bare spot at ventral margin of antennal groove. Gena high, gena-to-eye ratio 0.33 or larger, height subequal to combined length of pedicel and basal flagellomere. Maxillary palpus yellow. Thorax: Mesonotum whitish gray. Forefemur lacking anteroventral row of closely set setulae. Abdomen: Dorsum unicolorous, gray, slightly darker and less microtomentose than mesonotum; sternite 5 of male about 3 × length of anterior width, gradually becoming wider posteriorly, posterior margin deeply emarginate, bearing numerous, short, setulae medially. Male terminalia (Figs 196-198): Epandrium short, length of portion ventrad of cercal cavity less than cercal height, width in posterior view (Fig. 196) greatest at level of ventral margin of cerci, thereafter turned medially toward ventral margin, ventral margin whole, not bifurcate, moderately wide, width slightly Greater than that of cercal cavity, slightly more produced medioventrally but with a shallow lateral swelling bearing patch of 5-6, moderately long setulae; cerci elongate, narrowly semi-hemispherical, fused ventrally.

Type material.

The holotype male of Hecamedoides buccata Cresson is labeled "Wildwood N[ew]J[ersey. Cape May Co.] VII, 18, 1908 [18 Jul 1908]/♂/TYPE Hecamedoides BUCCATA E.T.Cresson,Jr. 6367 [red; species and generic names and type number handwritten]." The holotype is double mounted (minuten in a rectangular card), is in excellent condition, and is deposited in the ANSP (6367).

Type locality.

NEW JERSEY. Cape May: Wildwood (38°59.5'N, 74°48.9'W).

Other specimens examined.

Nearctic. CANADA. NEW BRUNSWICK. Shippigan (47°44.5'N, 64°42.9'W), 14 Jul 1931, J. M. Aldrich (1♂; ANSP).

ONTARIO. Wainfleet (42°55.3'N, 79°22.5'W), 26 Jul 1921, M. C. Van Duzee (1♀; USNM).

QUEBEC. Trois Rivieres (46°21.3'N, 72°34.9'W), 6 Aug 1930, A. L. Melander (1♂; ANSP).

UNITED STATES. ARIZONA. Apache: St. Johns (34°30.4'N, 109°20.7'W), 12 Jun 1950 (1♀; USNM). Mohave: Adamana Road (34°55.1'N, 114°08.3'W), 12 Jun 1950 (3♂, 4♀; USNM); Littlefield (Virgin River; 36°53.2'N, 113°55.8'W), 7 Apr 1968, W. N. Mathis (1♂; USNM). Navajo: Joseph City (34°57.4'N, 110°19.9'W), 12 Jun 1950 (1♂; USNM); Kayenta (36°44.4'N, 110°14.4'W), 14 Apr 2003, W. N. Mathis, T. Zatwarnicki (3♂, 1♀; USNM).

FLORIDA. Volucia: Daytona Beach (29°12.6'N, 81°01.4'W), 23 Jan-5 Feb 1936, 1939, A. L. Melander (4♂, 1♀; ANSP, USNM).

KANSAS. Riley: Manhattan (39°11'N, 96°34.3'W), 9 Jun 1934, C.W. Sabrosky (1♀; USNM). Wallace: Wallace (38°54.7'N, 101°35.5'W), Jul 1885 (1♂; ANSP).

MARYLAND. Calvert: Chesapeake Beach (38°41.2'N, 76°32.1'W), 23 Jun-27 Jul 1913, 1931, C. P. Heinrich, F. K. Knab (3♂, 2♀; ANSP, USNM). St. Mary’s: Saint George Island (38°07.2'N, 76°29'W; Seaside), 23 Jun 1931, A. L. Melander (1♂; USNM).

MASSACHUSETTS. Barnstable: Falmouth (41°33.1'N, 70°36.9'W), 9 Jun-1 Jul 1930, A. L. Melander, A.H. Sturtevant (2♀; USNM); South Yarmouth (41°40'N, 70°11.1'W), 1 Aug 1939, A. L. Melander (1♂, 1♀; USNM).

MICHIGAN. Bay: Bay City (43°35.7'N, 83°53.3'W), 30 May 1934, G.C. Steyskal (1♂; ANSP). Clare: Clare (43°49.2'N, 84°46.1'W), 12 Jul 1941, R.R. Dreisbach (1♀; USNM). Hillsdale: Somerset (42°02.9'N, 84°22.6'W), 12 May 1952, A.H. Sturtevant (1♂; USNM). Wayne: Grosse Ile (42°07.7'N, 83°08.7'W), 8 Aug 1954, G.C. Steyskal (5♂, 8♀; USNM).

MINNESOTA. Bigstone: (45°22.4'N, 96°31'W), 5 Jun 1938, C. E. Mickel (1♀; USNM).

MONTANA. Sheridan: Medicine Lake (48°30.2'N, 104°30'W), 9 Jun 1969, W. W. Wirth (1♀; USNM).

NEBRASKA. Cherry: Snake River (42°33.4'N, 101°53.6'W), 2 Jun 1969, W. W. Wirth (3♀; USNM). Lancaster: Lincoln (40°48.4'N, 96°40.9'W), 19 Jun 1969, W. W. Wirth (1♀; USNM).

NEVADA. Clark: Bunkerville (36°46.4'N, 104°07.7'W), 20 May 1952, A. H. Sturtevant (1♀; USNM).

NEW HAMPSHIRE. Coos: Pickham Notch (44°15.4'N, 71°15.2'W), 9 Jul 1931, A. L. Melander (1♀; USNM).

NEW JERSEY. Cape May: Wildwood (38°59.5'N, 74°48.9'W), 18 Jul 1908 (3♂, 2♀; ANSP).

NEW MEXICO. Curry: Melrose (34°25.8'N, 103°38'W), 22 May 1954, A. H. Sturtevant (1♂; USNM). Colfax: Cimarron (36°30.4'N, 104°55.2'W; river margin), 26 May 1969, W. W. Wirth (1♀; USNM). Taos: Rio Grande (34°16'N, 106°46.2'W), 6 Jul 1953, W. W. Wirth (2♀; USNM). Socorro: Socorro (34°03.5'N, 106°53.5'W), S. D. Williston, 1916 (1♂; USNM).

NEW YORK. St. Lawrence: Coles Creek State Park (44°53.5'N, 75°08.5'W), 10 Aug 1976, S. R. Alm (1♂, 1♀; USNM).

NORTH CAROLINA. Dare: Nags Head (35°57.5'N, 75°37.5'W), 15 Jul 1959, W. W. Wirth (2♀; USNM).

NORTH DAKOTA. Bowman: Bowman-Haley Dam and Reservoir (45°59.5'N, 103°15.4'W; 840 m), 19 Jun 2008, D. and W. N. Mathis (16♂, 2♀; USNM).

OHIO. Mercer: Grand Lake, St. Marys (near Montezuma) (40°30.3'N, 84°32.4'W), 26 May 1977, B. A. Steinly (1♂; USNM).

OKLAHOMA. Alfalfa: Great Salt Plains (36°43.2'N, 98°10.7'W; salt marsh), 22 May 1969 (1♂; USNM).

PENNSYLVANIA. Erie: Presque Isle State Park (40°08.6'N, 80°08.1'W), 6 May 1977, B. A. Steinly (1♂; USNM).

RHODE ISLAND. Washington: Watch Hill (41°18.8'N, 71°51'W), 5 Aug 1939, A. L. Melander (1♀; USNM).

SOUTH DAKOTA. Lawrence: Beaver Creek (43°02.5'N, 100°09.5'W), 15 Jun 1969, W. W. Wirth (1♀; USNM). Mellette: Little White River (43°13'N, 101°0.9'W; river margin), 4 Jun 1969, W. W. Wirth (8♂, 6♀; USNM).

UTAH. Emery: Green River (3.3 km N; 39°01.7'N, 110°09.7'W; 1253 m), 19 Jul-5 Aug 1988, 1992, W. N. Mathis (7♂, 2♀; USNM). Garfield: Alvey Wash (8.4 km S Escalante; 37°42.3'N, 111°37.6'W; 1880 m), 21 May 2001, D. and W. N. Mathis (1♂, 1♀; USNM); Deer Creek (37°51.2'N, 111°21.1'W; 1762 m), 21 May 2001, D. and W. N. Mathis (2♂, 1♀; USNM); Willow Tank-Hurricane Wash (37°23.2'N, 111°08'W; stock tank), 22 May 2001, D. and W. N. Mathis (4♂, 1♀; USNM). Grand: Crystal Geyser (38 56.3'N, 110 8.1'W; 1000 m), 15 Aug. 2008, D. & W. Mathis (1♂; USNM); Green River (15.3 km N; 39°7'N, 110°6.6'W; 1255 m), 30 Jul-15 Aug 2007, 2008, D. and W. Mathis (10♂, 7♀; USNM); Thompson Springs (9 km N, 39°2.3'N, 109°43.4'W; 1740 m) 1 Aug 2007, D. and W. Mathis (20♂, 8♀; USNM). Kane: Drip Tank Canyon (37°19.4'N, 111°31.8'W), 15 May 2001, D. and W. N. Mathis (4♂, 1♀; USNM); East Fork of Virgin River (26.6 km N Knab; 37°12.2'N, 112°41.4'W), 18 May 2001, D. and W. N. Mathis (3♂, 1♀; USNM); Kanab Canyon (6.5 km N Kanab; 37°08.7'N, 112°32.4'W), 14 May 2001, D. and W. N. Mathis (3♂, 2♀; USNM); Seaman Wash (24.5 km E Kanab; 37°07'N, 112°15'W), 14 May 2001, D. and W. N. Mathis (1♂; USNM); Sheep Creek (37°29.7'N, 112°04'W), 17 May 2001, D. and W. N. Mathis (4♂, 1♀; USNM); Sheep Creek, junction Skutumpah Road (37°29.7'N, 112°03.9'W; 1800 m), 12 May 2000, K. T. Huntzinger, W. N. Mendel, C. R. Nelson (1♂, 1♀; USNM); Willis Creek (37°29'N, 112°05.8'W), 17 May 2001, D. and W. N. Mathis (3♂, 1♀; USNM). San Juan: Blanding, Recapture Reservoir (37°39.9'N, 109°26.5'W; 1840 m), 23 Jul 2013, D. and W. N. Mathis (3♂, 1♀; USNM).

VERMONT. Chittenden: Burlington (44°28.9'N, 73°13.5'W), 1 Sep 1937, A. L. Melander (1♀; ANSP).

VIRGINIA. Accomack: Assateague Island, Toms Cove (37°53.3'N, 75°20.6'W), 4 Oct 2005, D. and W. N. Mathis (16♂, 8♀; USNM); Assateague Island, Toms Cove (37°53.1'N, 75°20.7'W), 15 Jun 2007, D. and W. N. Mathis (1♀; USNM). Westmoreland: Popes Creek (G. Washington birthplace; 38°13.7'N, 76°54.6'W), 16 Sep 1994, W. N. Mathis (11♂, 4♀; USNM). Independent City: Virginia Beach City, Cape Henry (36°55.9'N, 76°01.2'W), 28 Jun 1939, A. L. Melander (1♂; USNM).

WYOMING. Crook: Alva (near; 44°38.6'N, 104°22.8'W; 1330 m), 20 Jun 2008, D. and W. N. Mathis (♂, ♀; USNM). Niobrara: Lusk (64.5 km N; 43°21'N, 104°13'W), Jul 1905 (1♂; ANSP).

Distribution

(Fig. 199). Nearctic: Canada (New Brunswick, Ontario, Quebec). United States (Arizona, Florida, Kansas, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Utah, Vermont, Virginia, Wyoming).

Remarks.

This species was included in the genus Hydrochasma for most of the last century and there is superficial resemblance with species of that genus. Structures of the male terminalia, however, indicate that this species is clearly in the genus Discocerina where Zatwarnicki and Mathis (2001) placed the species. The high gena is distinctive among congeners in the Nearctic Region.