Gymnoclasiopa parilis (Cresson)

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012, A revision of the New World species of Gymnoclasiopa Hendel (Diptera, Ephydridae), ZooKeys 248, pp. 1-69 : 31-34

Gymnoclasiopa parilis (Cresson) Figs 41-44

Ditrichophora parilis Cresson 1924: 160; 1942: 119 [review]. Wirth 1965: 739 [Nearctic catalog].

Gymnoclasiopa parilis . Mathis and Zatwarnicki 1995: 177 [generic combination; world catalog].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.60-2.60 mm, generally black with moderately to very sparsely gray microtomentose dorsally. Head: Frons moderately gray microtomentose on black background color; fronto-orbits gray. Scape black, pedicel mostly grayish black but with apex yellowish red; basal flagellomere blackish gray dorsoapically, yellowish to reddish basoventrally; arista bearing 5 dorsal rays. Face somewhat flat, although antennal grooves, especially ventral margins, relatively conspicuous; facial microtomentum distinctive, generally silvery white; genal height greater than height of basal flagellomere, gena-to-eye ratio 0.13-0.15, silvery white, concolorous with face. Maxillary palpus black. Thorax: Mesonotum thinly microtomentose, subshiny with some metallic luster, especially medially; grayish black; pleural areas gray to brownish gray, subshiny. Wing hyaline; costal vein ratio 0.36-0.43; M vein ratio 0.52-0.61; halter stem brown to blackish brown; knob whitish yellow to yellow. Coxae, femora and tibia concolorous grayish black to black, microtomentum sparse; tarsi mostly yellow, apical tarsomeres darker, more grayish black. Abdomen: Tergites largely shiny black, very sparsely microtomentose. Male terminalia (Figs 41-43): Epandrium in posterior view (Fig. 41) as a moderately rounded, inverted U with the base more narrowly formed, width of dorsal portion slightly narrower than lateral arms, lateral arms shallowly arched, setulae more clustered at ventral margin; cercus in posterior view (Fig. 41) elongate, evenly oval, dorsal margin very slightly more narrowly rounded than ventral margin, setulae more clustered at ventral margin; aedeagus in lateral view (Fig. 43) slipper-like, base shallowly emarginate, tapered gradually toward apex, apex moderately broadly rounded, in ventral view (Fig. 42) expanded laterally from narrow base on basal 1/3, thereafter to apex almost parallel sided, apical margin moderately deeply incised medially, bilobed; phallapodeme in lateral view (Fig. 43) more or less irregularly triangular, extension toward hypandrium more elongate than angle towards aedeagal base, in ventral view (Fig. 42) I-shaped, apical crossbar robust, wider than basal crossbar, apical margin very shallowly emarginate; ejaculatory apodeme in lateral view robustly comma-shaped, in ventral view L-shaped; postgonite in lateral view (Fig. 43) robustly bar-like, basal 1/3 angulate, narrower than extended, mostly parallel-sided apical 2/3, bearing 3-4 setulae along posterior margin and 2 setulae subapically along anterior margin, in ventral view (Fig. 42) as an elongate triangle, wide basally, tapered to narrowly rounded apex; pregonite in lateral view (Fig. 43) moderately elongate, straight, clavate, wider apically than narrow base, in ventral view (Fig. 42) robustly J-shaped with pointed, curved base and expanded apex; hypandrium in ventral view (Fig. 42) almost quadrate, as wide as long, anterior margin shallowly curved, lateral margins curvey, posterior margin broadly and moderately deeply emarginate, forming wide pocket, in lateral view (Fig. 43) narrowly elongate, shallowly sinuous.

Type material.

The holotype male of Ditrichophora parilis Cresson is labeled "Bar Harbor 4 VIII. 18. [August 18; date handwritten] Me [Maine. Hancock:]/♂/M. C. Z. Type 31758 [red; number handwritten]/TYPE Ditrichophora PARALIS [sic; parilis] E. T. Cresson, Jr. [maroon; species name handwritten]." The holotype is directly pinned, is in good condition (thorax partially broken where pin is inserted), and is deposited in the MCZ (31758). Cresson (1924: 160) noted that C. W. Johnson was the collector.

Type locality.

United States. Maine. Hancock: Bar Harbor (44°18.7'N, 68°12.2'W).

Other specimens examined.

Nearctic. CANADA. BRITISH COLUMBIA. Waterfall at Peterson Creek # 4, Alaska Highway DC 445 (52°24'N, 121°38'W), 29 Jun 1978, P. H. Arnaud, Jr. (1♀; CAS).

NORTHWEST TERRITORIES. Aklavik (68°13.6'N, 135°0.7'W), 12 Jun-15 Sep 1931, O. Bryant (1♂, 3♀; USNM).

UNITED STATES. ALASKA. Fairbanks North Star: Fairbanks, Lake Ballaine (64°52.2'N, 147°49.5'W; 160 m), 2 Aug 2011, D. and W. N. Mathis (1♂, 3♀; USNM). Kenai Peninsula: Kenai Lake (60°20.5'N, 149°22.2'W; Primrose Campground), 31 Jul 2002, 2003, D. and W. N. Mathis (2♂, 2♀; USNM); Kenai River, Jim’s Landing (60°28.9'N, 150°06.9'W), 3 Aug 2002, D. and W. N. Mathis (2♂; USNM); Skilak Lake (60°26.3'N, 150°19.4'W), 3 Aug 2002, D. and W. N. Mathis (1♀; USNM). Matanuska-Susitna: Eklutna (Knik Arm; 61°28.2'N, 149°21.4'W), 7 Aug 2002, D. and W. N. Mathis (1♂; USNM); Glennallen (96.5 km W Glennallen; 61°55.6'N, 147°13.6'W), 7 Aug 2012, D. and W. N. Mathis (1♀; USNM); Knik River (61°27.8'N, 148°51.6'W), 5 Aug 2002, D. and W. N. Mathis (21♂; USNM); Matanuska (61°32.5'N, 149°13.8'W; rotary trap), 29 Apr 1944, J. C. Chamberlin (1♂, 4♀; USNM); Matanuska Flats (N Palmer; 61°16'N, 150°16'W), 17 Jul 1971, B. A. Foote (1♂; USNM); Sheep Creek (61°58.3'N, 150°05'W; 55 m), 10 Aug 2011, D. and W.N. Mathis (3♂, 5♀; USNM); Talkeetna (62°18.9'N, 150°06.3'W), 10 Aug 2011, D. and W. N. Mathis (1♀; USNM); Willow Creek (61°46.1'N, 150°04.2'W; 50 m), 10 Jul 2006, D. and W. N. Mathis (1♂; USNM). Southeast Fairbanks (Census Area): Delta Junction (8 km S; 63°51.5'N, 145°44.6'W), 11 Aug 2003, D. and W. N. Mathis (1♂; USNM); Gardiner Creek Camp, Alaska Highway DC 1253 (62°51.5'N, 141°28'W), 5 Aug 1978, P. H. Arnaud, Jr. (1♂; CAS); Tok River, GJ-97.9 (62°21.8'N, 142°50.5'W), 4 Aug 1978, P. H. Arnaud, Jr. (1♀; CAS). Valdez-Cordova (Census Area): Chitina (61°30.9'N, 144°26.2'W), 15-18 Jun 1953, W. C. Frohne (2♂, 2♀; USNM; WSU); Lower Tonsina Valley (61°39.3'N, 144°39.5'W), 19 Aug 1953, W. C. Frohne (1♀; WSU); Tolsona Creek State Campground, Glenn Highway, A 173 (62°03.9'N, 145°59.8'W), 31 Jul 1978, P. H. Arnaud, Jr. (2♂, 1♀; CAS). Yukon-Koyukuk (Census Area): Circle Hot Springs (65°49.5'N, 144°03.6'W), 26 Jul 1971, B. A. Foote (2♂, 3♀; CMNH, USNM).

CALIFORNIA. San Mateo: Stanford University (37°24'N, 122°14.5'W), 15 Jul, A. L. Melander (1♀; ANSP).

CONNECTICUT. Litchfield: Kent Falls (41°46.7'N, 73°25'W), 28 Aug 1940, A. L. Melander (1♂; USNM).

MAINE. Hancock: Bar Harbor (44°23.3'N, 68°12.3'W), 2 Jul 1921, C. W. Johnson (1♀; ANSP); Cadillac Mountain (44°21.1'N, 68°13.4'W), 25 Jul 1914 (1♂; ANSP). Somerset: Caratunk (45°14'N, 69°59.4'W), 2 Aug 1950, A. H. Sturtevant (1♀; USNM).

MASSACHUSETTS. Hampden: Chester (42°16.4'N, 72°56.6'W), 12 Jul 1912, C. W. Johnson (1♂; ANSP).

NEW HAMPSHIRE. Coos: Dolly Copp (44°19.9'N, 71°13.1'W), 13 Jul 1931, A. L. Melander (1♀; USNM). Grafton: White Mountains, Stinson Lake (43°51.7'N, 71°48.5'W), 23 Jul 1961, W. W. Wirth (1♂, 1♀; USNM).

NEW YORK. Cattaraugus: Stoddard Hollow (42°04'N, 78°45.5'W; 550-580 m), 10 Aug 1961, D. L. Deonier (7♂, 7♀; USNM). Hamilton: Shanty Brook (43°17.2'N, 74°33.4'W; 520 m), 5 Aug 1961, D. L. Deonier (4♂, 2♀; USNM).

Distribution

(Fig. 44). Nearctic: Canada (British Columbia, Northwest Territories, Quebec, Yukon Territory), United States (Alaska, California, Connecticut, Maine, Massachusetts, New Hampshire, New York,?Vermont [literature record, not confirmed; Cresson 1924: 160], Washington).

Remarks.

In collections that we studied, this was the species that was most often misidentified. Although similar to other congeners, it is distinguished most by the black maxillary palpus and tan to yellowish basitarsomere of the foreleg and halter stem. From Gymnoclasiopa grecorum , which also shares these character states just noted, it is distinguished by the ventrally reddish antennae (especially the basal flagellomere) and the black, subshiny postpronotum, notopleuron, and anepisternum.