THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 89 



Another female taken at Marshall Pass, Colorado, July 28, 1908, 

 has scarcely a trace of the brown clouding on the wings, except on 

 the veins, but no doubt it belongs to the same species — probably a 

 little immature. 



No. 48. DOLICHOPUS SETIFER Loew. 



Dolichopus setifer Loew, Neue Beitr., vol. 8, 1862, p. 12; N. Amer. Dipt., pt. 2, 

 1864, p. 30.— Aldrich, Kans. Univ. Quart., vol. 2, 1893, p. 156.— Melander 

 and Brues, Biol. Bull., vol. 1, 1900, p. 148.— Johnson, Insects of N. J., 1909, 

 p. 756. 



Male. — Length 4-4.2 mm,; of wing 3.75-4 mm. Face narrow, 

 silvery white, Front bright shining green. Antennae (fig. 48a) 

 wholly black; third joint about as long as wide, nearly round in 

 outline, but obtusely pointed at tip ; lateral and inferior orbital cilia 

 silvery white, the lower cilia flattened. 



Thorax bright shining green, sometimes with traces of two coppery 

 vittae at the front edge of the dorsum (in one specimen from Niagara 

 Falls, New York, there are two violet vittae extending nearly to the 

 middle of the dorsum) ; pleurae dulled with white pollen. Abdomen 

 shining green with slight bronze reflections and black incisures; the 

 white pollen on its sides abundant. Hypopygium black; its lamellae 

 of moderate size, somewhat triangular in* outline, white with the apical 

 border black, a little jagged and bristly at lower corner, with delicate, 

 mostly pale hairs on upper and lower edges. 



Coxae black with dark yellowish brown tips ; fore and middle coxae 

 with white hairs on their anterior surface, the former with the usual 

 black bristles at tip, still they appear almost white in certain lights in 

 many specimens. Femora green with yellow tips. Middle and hind 

 femora each with one preapical bristle, the latter with long black 

 cilia below, which appear white when viewed in certain lights; the 

 longest of these cilia twice as long as the width of the femora. Fore 

 and middle tibiae yellow; hind tibiae thickened, yellow on upper 

 edge for about two-thirds their length, black at tip, on .the sides more 

 brown at base or almost black, becoming black at half their length, 

 their bristles long and numerous. Fore tarsi slightly longer than 

 their tibiae, brown; first joint about as long as the three succeeding 

 joints taken together. Middle tarsi about as long as their tibiae, 

 black from the tip of the first joint. Hind tarsi wholly black, the 

 first joint with numerous large bristles on upper surface. Calypters 

 and halteres yellow, cilia of the former pale yellow. 



Wings (fig. 48) nearly hyaline with a black spot at tip, reaching 

 from the tip of the second vein to the apex of the wing and about as 

 wide as the length of the cross-vein; costa a little enlarged at tip of 

 first vein; last section of fourth vein a little bent before its middle; 

 hind margin of wing not indented at tip of fifth vein; anal angle 

 obsolete, the wing being narrowed at base; root of wing yellow. 



