Xylophagus decorus Williston 1885

Xylophagus decorus Williston
1885. Xylophagus decorus Williston, Can. Ent., xvn, p. 121.
1908. Erinna decora Kertesz, Cat. Dip., 111, p. 136.
Shining black; legs except tip of tarsi, reddish yellow, hind tibiae darkened in male; antennae longer than head; wings with a brownish cloud under stigma and apex clouded.
Male. — Moscow Mountain, Idaho, July 25, 1920, (R. C. Shannon), [Shannon collection]. (Allotype. Here described for the first time.) Length, 11-12 mm. Similar to female except as follows: front noticeably narrower; antennae wholly black; mesonotal stripes grayish rather than brownish; hind tibiae dark brownish on upper surface.
Female. — Length, 13 to 15 mm. Head: Front described as "but little shining, thinly brownish dusted." In specimens before me the front is undoubtedly rubbed for it is shining black except on upper part and sides where it is grayish pollinose; vertex, including ocellar tubercle, and lower two-thirds to half of face shining black, upper part of face gray pollinose; antennae blackish, described as "tip of first joint and second more reddish brown"; the specimens before me have the reddish brown on inner side of second segment in but one case, the others wholly black; antennae longer than head (measured from above), the first segment at least half as long as the remaining ones taken together; the first two segments with fine black hairs, the remaining ones grayish or brownish pollinose in certain lights; palpi and proboscis blackish, the latter tinged with brownish, both with fine black hairs.
Thorax: Mesonotum broadly shining black on lateral and caudal borders, with two broad stripes of brownish pollen, narrowly separated on median line; pleura shining black; metanotum with short fine, pale hairs; halteres, with knob yellowish to reddish brown, the stalk somewhat darkened. Abdomen: Blackish, shining, with short fine black hairs (which in the Mary's Peak, Ore., specimen appear in certain lights paler).
Legs: A dark reddish yellow, including coxae; last two segments of tarsi blackish.
Wings: Veins dark brown; membrane suffused faintly with pale brownish; a band arising beyond tip of scutellum, narrowing and evanescent just before anal border, a spot at apex of discal cell and the apex broadly, distinctly marked with brownish, but markings sometimes very faint.
Holotype. — Female; Washington Territory, (-H. K. Morrison), [University of Kansas].
Specimens Examined: About 22 males and females.
Saskatchewan: i 9, Strathcona, Regina, May 20, 1905, (T. N. Willing), British Columbia: i & , 1 9 , Kaslo, June 2, (H. G. Dyar), [U. S. N. M.]. 1 d Vancouver, (R. H. Crystal), [Ent. Br., Dept. Agr. Canada]; 1 9, May 6, 1919, (R. S. Sherman); 1 d% May 23, 1918, (R. S. Sherman); 1 9, May 5, 1907, (R. S. Sherman); and 1 9 , April 25, 1905 (R. S. Sherman), [all Sherman]. 1 9 , June 6, 1903, [Sherman]. 1 9, Kokanee Mt., 9000 ft., Aug. 8, 1903, (R. P. Currie), [U. S. N. M.]. 1 9, Lillooet, May 17, 1916, [Hine]. 2 d 1 9, Carbonate to Prairie Hills, July 12-18, 1908, (J. C. Bradley), [C. U.].»
Washington: 3 9, Hoquiam, April 30, 1904, May 12 and 14, 1904, (Burke), [U. S. N. M.]. 1 9, "Wash. Terr." (H. K. Morrison), [Kansas; type].
Oregon: i d Coruallis, May 17, 1917, (Winter), [Cole]. 1 9, Mount Hood, [M. C. Z.]. 1 9, Mary's Peak, May 16, 1914, (L. G. Centner), [Cole].
Idaho: i 9, Moscow Mountain, July 12, [A. L. Melander]; 1 d July 25, 1920, (R. C. Shannon), [Shannon; allotype].
Colorado: i 9 , Wolf-Fall Creeks, 7000 ft., June 20, (F. E. Lutz), [A. N. N. H.].
New Hampshire: i 9, Franconia, (A. T. Slosson), [A. M. N. H.].
Virginia: i 9, Roslyn, April 23, 1913, (R. C. Shannon), [A. N. M. H.].
Two males from "Col" determined by Coquillett as decorus [U. S. N. M.] have the antennae short and the front somewhat produced; both as in the female of lugens Loew. They undoubtedly belong to this species, however.

Xylophagus decorus is a species of fly in the family Xylophagidae.