Polytrichophora salix, Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012

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 : 58-60

Polytrichophora salix sp. n. Figs 99103

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.70-2.30 mm.

Head: Frons dull, moderately to heavily microtomentose, mesofrons grayish brown to grayish black, more grayish anteriorly and on ocellar tubercle; parafrons black with gray microtomentum, slightly grayer anteriorly; fronto-orbits silvery gray microtomentum. Antenna short, mostly yellowish orange but black dorsally, basal flagellomere short, length subequal to height of pedicle, slightly darker, more brownish yellow; arista with 5 dorsal rays. Face wider than combined length of pedicel and basal flagellomere; face densely microtomentose, seriaceus, yellowish to lightly golden white; parafacial and gena mostly faintly golden white, becoming silvery white; parafacial with moderate ventral dilation; gena moderately short, height subequal to height of basal flagellomere, eye-to-cheek ratio 0.19-0.22.

Thorax: Mesonotum mostly subshiny, moderately densely microtomentose, mostly brown but becoming grayer anterolaterally; pleural areas mostly gray. Wing generally infumate, light to dark brown; anterior margin of wing lacking spine-like setae; costal vein ratio 0.68-0.71; M vein ratio 0.50-0.56. Forefemur lacking row of 9-10 short, stout setae along apical half of anteroventral surface; forefemur with row of 7-9, longer, evenly spaced posteroventral setae; femora and tibia mostly gray, apices slightly yellowish; tarsi yellow, especially ventrally, often blackish dorsally, apical 1-2 tarsomeres brown.

Abdomen: Subshiny blackish gray; tergites 1-3 about equal, shorter than tergites 4-5; dorsum of male tergite 5 entirely black, similar to preceding tergites, posterior margin bluntly rounded to truncate, not bearing row of 6-10, distinctly larger setulae along posterior margin with posterodorsal orientation; sternites 4-5 of male without dense row of setulae along posterior margin. Male terminalia (Figs 99-102): Epandrium in posterior view (Fig. 99) generally as an inverted pear, pyriform, widest a midheight, conspicuously narrowed on ventral 1/3, uniformly setulose, dorsal margin rounded, both ventral extensions robustly developed, with short, acute point apicomedially, in lateral view (Fig. 100) generally shallowly arched, ventral apex moderately acutely pointed, cercus large, conspicuous; aedeagus tubular, in lateral view (102) distinctly L-shaped medially, apex tapered to acute point, in ventral view (Fig. 101) elongate, straight, tapered toward apex, lateral margins nearly straight; phallapodeme in lateral view (Fig. 102) elongate, keel in lateral view shallowly developed apically as a narrow, almost digitiform projection, in ventral view (Fig. 101) bluntly clavate at attachment with aedeagal base, opposite end T-shaped; gonite in lateral view (Fig. 102) narrowly elongate, shallowly curved, in ventral view (Fig. 101) angularly arched, slightly wider toward base of aedeagus; hypandrium in lateral view (Fig. 102) moderately elongate with long, digitiform posterior projection, in ventral view (Fig. 101) H-shaped with anterior extensions abutting anteriorly, posterior arms digitiform projections slightly flared laterally.

Type material.

The holotype male is labeled "USA A[LAS]K[A]. Mat[anuska]-Su[sitna]: Willow Creek (61°46.1'N, 150°04.2'W; 50 m), 10 July 2006,D.&W.N.Mathis/USNM ENT 00285962 [plastic bar code label]/HOLOTYPE ♂ Polytrichophora salix Mathis & Zatwarnicki, USNM [red]." The holotype is double mounted (minuten pin in a block of plastic), is in excellent condition, and is deposited in the USNM. Seven paratypes (4♂, 3♀; USNM) bear the same label data as the holotype. Other paratypes are as follows: 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♀; USNM). Kenai Peninsula: Homer (59°38.8'N, 151°31.5'W), 2 Aug 2002, D. and W. N. Mathis (2♂; USNM). Matanuska-Susitna: Talkeetna (62°18.9'N, 150°06.3'W), 4 Aug 2003, 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 (5♂, 3♀; USNM). Valdez-Cordova (Census Area): Gulkana River (19.3 km N Glen nallen; 62°16.1'N, 145°23.1'W), 7 Aug 2011, D. and W. N. Mathis (1♀; USNM); Valdez (4.8 km N; 61°05.8'N, 146°14.6'W), 8 Jul 2006, D. and W. N. Mathis (1♀; USNM).

Type locality. United States. Alaska. Matanuska-Susitna: Willow Creek (61°46.1'N, 150°04.2'W; 50 m).

Other Specimens Examined–Nearctic. UNITED STATES. ALASKA. Nome (Census Area): Pilgrim Hot Springs (65°05.6'N, 164°55.6'W), 3 Aug 2012, D. and W. N. Mathis (1♂; USNM).

IDAHO. Kootenai: Fernan Lake (47°40.5'N, 116°43.6'W), 16 Jul 1968, W. N. Mathis (1♂; USNM).

NEW MEXICO. Sandoval: La Cueva (Junction of Highways 126 & 4; 35°52'N, 106°38.4'W; 2342 m), 14 Jun 2011, D. and W. N. Mathis (1♂; USNM).

OREGON. Benton: Cary'S Grove (44°22.6'N, 123°36.1'W), 2 Sep 1974, W. N. Mathis (3♂, 1♀; USNM); Rock Creek (6.4 km SW Philomath; 44°30.1'N, 123°26.2'W), 29 May 1972, W. N. Mathis (2♀; USNM). Linn: Waterloo (44°29.6'N, 122°49.5'W), 24 Jul 1974, W. N. Mathis (1♂; USNM).

Distribution

(Fig. 103). Nearctic: United States (Alaska, Idaho, New Mexico, Oregon).

Etymology.

The species epithet, salix, is the Latin word for willow and refers to the type locality in Alaska, Willow Creek.

Remarks.

This species is distinguished from congeners of the orbitalis group externally by having the row of stout setae along the posteroventral surface of the forefemur short (length less than width of foretibia) and male tergite five is bluntly rounded to truncate. Among characters of the male terminalia that distinguish this species are the following: Epandrium in posterior view (Fig. 99) generally as an inverted pear, pyriform, widest a midheight; both ventral epandrial extensions are robustly developed, with short, acute point apicomedially; hypandrium in ventral view (Fig. 101) H-shaped with anterior extensions abutting anteriorly, posterior arms as digitiform projections that are slightly flared laterally.