Arthropeas magna Johnson 1913

Arthropeas magna Johnson
1913. Arthropeas magna Johnson, Can. Ent., XL, p. 11.
Stout flies greatly resembling in the general appearance of both sexes Coenomyia ferruginea Scopoli. Blackish, the whole body and face more or less densely hairy ; mesonotum dull yellow pollinose, almost obscured by three broad black stripes; abdomen shining black, segments 1 to 4 each with a broad apical yellowish band more or less interrupted on the median line; legs brownish yellow, femora darker; wings strongly tinged with brownish, especially along costal border and through the middle.
Male. — Length, 12 mm. Head: Face blackish overlaid by dull yellowish pollen, clothed on sides with moderately long, dense black hairs; palpi and proboscis brownish yellow, the former with a few black hairs mostly towards tip, the latter with some pale hairs at base; antennae brownish yellow, first two segments with a few black hairs, directed forward, longer and more numerous beneath; the flagellum apparently seven-segmented, acute at tip.
Thorax; Mesonotum black, with four dull yellow pollinose stripes, the lateral ones broader and touching the notopleural suture, the inner ones narrower, but expanding at each end, particularly caudad and connected with the lateral stripes; the black areas between the yellow stripes subshining caudad of the transverse suture; scutellum dull black, together with the mesonotum rather densely clothed with moderately long black hairs, which on the lateral margins become longer and
yellowish; pleura blackish, thinly clothed with long pale hairs, occasionally intermixed with a few black ones especially below, a dense tuft of yellowish hairs on metapleural swelling; halteres dirty yellowish; metanotum black, with pale hairs on sides, in the middle bare and shining.
Abdomen: Black, shining along median line and on lateral margins, the caudal margins of the first four segments each with a broad somewhat yellowish pollinose band which is more or less contracted on the median line and on the lateral borders, that on the first segment usually being entirely interrupted on the median line; clothed with rather dense, moderately long, somewhat recumbent hairs which are black on the black parts and pale on the yellow bands; vertex almost wholly brownish yellow.
Legs: Coxae blackish, thinly brownish yellow pollinose, hairs black; remainder of legs brownish yellow, femora a little darker, especially on upper surface, tip of hind tibiae slightly darker, tarsi little if any darkened even at apex.
Wings: Strongly tinged with yellowish brown, an irregular darker area in middle from stigma through base of discal cell and also darkened along the free part of Cu; veins brownish; stigma diffuse, brownish, but little differentiated
Female. — Length, 14 to 15 mm. Similar to the male with the following differences; front and occiput as well as face yellowish brown pollinose, hairs on sides of face shorter, less dense and erect, and pale yellowish; front, measured just above antennae about one-fourth total width of head, somewhat narrowed above so that at vertex it is hardly twice the width of the ocellar tubercle; front with five fine longitudinal more or less well defined grooves, the median one usually obsolete above, but sometimes broken up into three indistinct smaller grooves just below the ocelli; the lateral grooves often interrupted near the middle; mesonotal stripes usually more prominent and a brighter yellow than in the male; mesonotum and scutellum less hairy than in male; abdomen somewhat more shining but less hairy than in male, brownish black, the pollinose bands on first, second and third segments broadly interrupted along the median line.
Holotype — Male; Beulah, Manitoba, [B. S. N. H.]. Allotype.— Female, topotypical, [B. S. N. H.]. Paratype. — 1 d" ; topotypical, Specimens Examined: 1 2 ; 8 males, 4 females.
Manitoba: 2 cf, i 9, Beulah, (type series). 1 cf, 1 9, Aweme June 14, 1911, June 24, 1904, (N. Criddle), [A. N. S. P.]. 1 d", Aweme, June 20, 1914, [U. S. N. M., ex Aldrich]. 1 cf, June 20, 1913, 1 9, June 25, 1913, Aweme, (N. Criddle); 1 9, Aweme, July 16, 1917, (N. Criddle); 1 cf, Treesbank, June 24, 1923, (R. M. White), [all C. N. M.].
Alberta: i cf, Calgary, [C. N. M.].
Montana: i cf, Mystic Lake, 6700 ft., July 4, 1902, [A. L. Melander].
This species has been recorded from Hill City, South Dakota, by C. H. T. Townsend. No female I have seen except the allotype has the scutellum "with three transverse ridges" ; the paratype female in the Museum of Comparative Zoology could hardly be described as possessing them.