Arthroceras pollinosum Williston 1886

Arthroceras pollinosum Williston
1886. Arthroceras pollinosum Williston, Ent. Am., II, p. 108.
1910. Arthroceras pollinosus Coquillett, Proc. U. S. Nat. Mus., xxxvn, p. 510.
Blackish in ground color but wholly heavily overlaid by pollen which in the male is for the most part light grayish, except on the thorax, where it is almost wholly ochraceous and on the abdomen where it is somewhat tinged with ochraceous. In the female the abdomen is more nearly wholly ochraceous pollinose and the upper
28 Previously reported from Mount Washington by Johnson (1913: 10).
part of the pleura are somewhat tinged with this color; antennae in both sexes blackish, paler towards base, legs a rather dirty yellow, in female tarsi blackish except base broadly, in male femora mostly and tarsi except base narrowly, blackish. Wings strongly tinged with ochraceous.
Male. — Length, 5.5 mm. Head: Face and frontal triangle light gray pollinose, sides of face bare ; palpi and proboscis blackish with fine whitish hairs, longer and more numerous on the former; cheeks and frontal triangle with long abundant whitish hairs; antennae bare, blackish except the third segment and the tip of the second which are paler.
Thorax: Mesonotum and scutellum heavily ochraceous pollinose, the latter more grayish on the margin, both with long fine whitish or yellowish hairs; pleura light gray pollinose, bare except for usual propleural and metapleural hairs and a few other scattered ones which are whitish; halteres brownish yellowish, the knobs blackish; metapleurum light gray pollinose.
Abdomen: Ground color black but heavily overlaid with light gray pollen which seems to be slightly tinged in some lights with ochraceous; above and beneath with rather abundant fine yellowish hairs, which are somewhat appressed on middle, longer and more erect on sides; hypopygium dark brown, somewhat shining.
Legs: Coxae light gray pollinose, hairs whitish or yellowish; femora except tip blackish, hairs pale; the tip of the femora, the tibiae wholly and the metatarsus except tip, brownish yellow; rest of tarsi blackish.
Wings: Membrane tinged with yellowish; veins also yellowish, darker towards apex; stigma elongate, pale brownish.
Female. — Length 5.5 to 8 mm. Similar to male except as follows: Front about two-thirds width of eye at narrowest point just above antennae, considerably wider on vertex ; both front and vertex grayish yellow pollinose and with somewhat satiny appearance, with a number of short yellowish hairs; pollen of face slightly tinged with ochraceous; palpi and proboscis reddish yellow, the former darker on tip; pleura above distinctly tinged with ochraceous; halteres wholly yellowish; abdomen with hind border of segments above and below, but more broadly above, ochraceous; legs wholly brownish yellow except the four terminal segments of the tarsi which are dark brownish; wing veins on the whole paler than in the male.
Specimens Examined: 13; 6 males, 7 females.
Washington: i d i 9, [U. S. N. M., ex Aldrich]. 1 d 1 9, Seattle, (O. B. Johnson), [U. of Washington].
Oregon: 2 d 9, Portland, June 6, 1915, (A. K. Fisher), [Biol. Surv.]. 1 d Corvallis, June II, 1925, (E. P. Van Duzee), [Calif. A. S.].
Idaho: 2 9, Moscow Mountain, July 6, 8, 1911, (A. L. Melander), [one specimen retained for the C. U. Collection].
Colorado: i d i 9, [U. S. N. M.]. i 9, Long's Peak Inn, 9000 ft., July 12, 1926, (E. C. Van Dyke), [Calif. A. S.]. 29
Wisconsin: i 9 , [A. M. N. H., ex. Wheeler].
29 Reported from Happy Hollow and Little Beaver and Clear Creek, by Johnson (1913: 10). The female from Wisconsin may possibly be a small teneral specimen of A . leptis O. S. but I place it here provisionally at least. There is a suggestion of the mesonotum being somewhat vittate but otherwise it is undoubtedly pollinosum. The July 8 female from Moscow Mt. measures about 9 mm.; it is in perfect condition and apparently a typical A . pollinosum.