Polytrichophora setigera (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 : 60-63

Polytrichophora setigera (Cresson) Figs 104108

Discocerina setigera Cresson 1916: 148.

Polytrichophora setigera . Cresson 1942: 114 [generic combination, review of Nearctic fauna]. Wirth 1965: 740 [Nearctic catalog]. Mathis and Zatwarnicki 1995: 186 [world catalog].

Polytrichophora orbitalis of authors, not Loew [misidentification]. Zatwarnicki and Mathis 2001: 49 [illustration of male terminalia from Jackson County, Oregon].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small shore flies, body length 1.60-1.95 mm.

Head: Frons largely dull to faintly subshiny, brown with moderate investment of gray microtomentum, anterior margin mostly concolorous, some specimens faintly orange; 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 0.13-0.16.

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 0.72-0.77; M vein ratio 0.48-0.55. 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, 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 subshiny with faint metallic tannish to dark gray luster medially, laterally gray; tergite 5 of male pointed, lacking distinctive row of setulae apically. Male terminalia (Figs 104-107): Epandrium in posterior view (Fig. 104) generally elliptical, more or less uniformly setulose, although slightly clumped dorsally and ventrally, dorsal margin broadly rounded, both ventral extensions pointed, narrowly connected dorsally, in lateral view (Fig. 105) with ventral apex acutely pointed; cercus relatively small but conspicuous; aedeagus tubular, in lateral view (Fig. 107) slightly tapered toward apex to bluntly rounded apex, in ventral view (Fig. 106) narrowly elongate with lateral margins very shallowly sinuous; phallapodeme in lateral view (Fig. 107) roughly triangular with extended keel bluntly rounded apically, in ventral view (Fig. 106) clavate with basal margin bluntly rounded; gonite in lateral view (Fig. 107) narrowly elongate, rounded angulate, angle obtuse, in ventral view (Fig. 106) conspicuously obtusely angulate, narrow, almost parallel sided; hypandrium in lateral view (Fig. 107) elongate, with lateral, irregular extension, in ventral view (Fig. 106) more or less as a rounded square with posterior, lateral arms.

Type material.

The holotype male is labeled "MesaGrande[,] SonomaCo[,] V 1908 Cal[ifornia]/JPBaumberger Collector/♂/Holo-TYPE Discocerina SETIGERA E. T. Cresson Jr [magenta; species and generic names handwritten]. The holotype is double mounted (minute pin in rectangular card), is in good condition, and is deposited in the ANSP (6101).

Type locality.

United States. California. Sonoma: Mesa Grande (32°56.6'N, 117°11.1'W).

Other specimens examined.

Nearctic. UNITED STATES. CALIFORNIA. Alameda: Berkeley Hills (37°53'N, 122°14.3'W), 11 Apr 1908 (3♂; ANSP). San Francisco: San Francisco (37°47.3'N, 122°29.7'W), 27 May 1908, F. E. Blaisdell (1♂; ANSP).

OREGON. Harney: Page Springs (42°47'N, 118°51'W; 1300 m), 6 Aug 2005, D. and W. N. Mathis (6♂, 2♀; USNM); Pike Creek (42°34.5'N, 118°31.7'W; 1320 m), 7 Aug 2005, D. and W. N. Mathis (2♂, 2♀; USNM). Jackson: Rogue Elk Park, Rogue River, (ca. 8 km NE Shady Cove; 42°39.4'N, 122°46.3'W), 28 Jul 1974, P. H. Arnaud, Jr. (1♂; USNM). Union: North Powder (3 km N; 45°03'N, 117°55.2'W), 13 Jul 1988, W. N. Mathis (1♀; USNM).

WASHINGTON. Asotin: Snake River at Grande Ronde River (48°04.8'N, 116°58.9'W;), 9 May 1915, A. L. Melander (1♂; ANSP). Franklin: Columbia River (NW Pasco; 46°21.5'N, 119°15.5'W), 29 Jul 1998, D. and W. N. Mathis (1♂; USNM); Pasco (3.2 km E; 46°15'N, 119°07'W), 8 Aug 1975, W. N. Mathis (1♀; USNM); Ringold (NW Pasco: 46°30.4'N, 119°15.3'W), 2-29 Jul 1988, 1998, D. and W. N. Mathis (8♂, 1♀; USNM); Sacajawea State Park (46°12'N, 119°02.4'W; 100 m), 12 Jul 1988, D. and W. N. Mathis (1♀; USNM).

Distribution

(Fig. 108). Nearctic: United States (California, Oregon, Washington).

Remarks.

Among congeners of the orbitalis group, this species 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 gradually tapered to apex; the hypandrium is large and more heavily sclerotized (Figs 104-107).