THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 135 

 No. 89. DOLICHOPUS SOCIUS Loew. 



Dolichopus socius Loew, Cent., vol. 2, 1862, p. 60; Mon. N. Amer. Dipt., pt. 2, 

 1864, p. 40. — Aldrich, Kansas Univ. Quart., vol. 2, 1893, p. 10. 



3Iale. — Length, 4.2 mm.; of wing, the same. Face rather wide, 

 silvery white, tinged with yellow on upper part. Front shining 

 green. Antennae black; first joint broadly yellow below; third large, 

 somewhat oval in outline, but pointed at tip, nearly t^^dce as long as 

 wide. Lateral and inferior orbital cilia whitish, only a few of the 

 upper cilia black. 



Thorax green with bronze reflections, which usually form more or 

 less distinct vittae on the front of the dorsum, where there is also a 

 little white pollen; pleurae dulled with white pollen. Abdomen 

 green with black incisures and bronze reflections; the white pollen 

 on the sides quite distinct. Hypopygium black; its lamellae rather 

 small, somewhat oval in outline, whitish, bordered with black on 

 apical margin, and more narrowly on upper edge, jagged and bristly 

 at apex, fringed with black hairs above. 



Fore coxae pale yellow, with silvery pollen and very minute pale 

 hairs on anterior surface. Middle and hind coxae black with yellow 

 tips. Femora and tibiae yellow. Middle and hind femora each with 

 one preapical bristle, the latter with a row of very delicate yellow 

 hairs on lower inner edge, these hairs are nearly one-fifth as long as 

 the width of the femora, still scarcely long enough to call cilia, the 

 black hairs on upper edge become long at base, the longest being 

 about three-fourths as long as width of femora. Posterior tibiae 

 shghtly thickened, their tips black for about one-sixth their length; 

 the glabrous stripe on upper surface quite distinct, although broken 

 up by the irregular placing of the large bristles and a few black hairs, 

 it extends upon the inner side of the tibiae at basal third. Fore tarsi 

 about one and a half times as long as their tibiae, yellow, tip of first 

 joint and the whole of second, thiid, and fourth joints, except their 

 extreme bases, black, fifth dark yellow; the joints of decreasing 

 length, first about as long as the two following taken together. Mid- 

 dle tarsi a little longer than their tibiae, black from the tip of the 

 first joint, still the apical half of fifth a little yellowish, usually quite 

 distinctly so. Hind tarsi wholly black. Calypters, their cilia, and 

 the halteres pale yellow. 



Wings (fig. 89) grayish; costa without enlargement at tip of fifth 

 vein; last section of fourth vein a very little bent just before its 

 middle; third vein bent backward at tip; hind margin of wing a 

 little indented at tip of fifth vein; anal angle nearly obsolete, the 

 wing being narrowed at base. 



Female.— Face wide, silvery white; third antennal joint smaller 

 than in the male; fore coxae with minute black hairs on anterior 

 surface; anal angle of wing a little more developed than in the male; 



