FAM. EMPIDID/E III 
I4. GENUS HESPEREMPIS, MELANDER 
Hesperempis, Melander, Ent. News, Philad. Vol. 17, p. 377 (1906); Williston, Man. N. Amer. Dipt. 
p. 226 (1908); Kertész, Cat. Dipt. Vol. 6, p. 84 (1909); Coquillett, Proc. U. S. Mus. Vol. 37, 
p. 551 (1910). 
Ragas, Melander (not Walker), Trans. Amer. Ent. Soc. Vol. 28, p. 276 (1902). 
» 
Characters.:— Bristleless, entirely opaque dusted, blackish or yellow species with yellow legs. 
Eyes separated, broadly so on the front, and in the male narrowly just beneath the antenne, the sides 
of the face diverging below, facets bare, of uniformsize in the female or the anterior slightly larger in the 
male; face of the female short and quadrate, the lower part retracted as the pollinose epistome; antennz 
inserted above the middle of the head, distinctly three-jointed, the first joint longer than the second, the 
basal joints with only a few microscopic hairs, the third joint compressed conical, terminated by a short 
two-jointed style whose basal segment is thick and whose outer segment is short and bristle-like; probos- 
cis very short and thick, the labella broad fleshy and hairy, palpi flattened, as long as the proboscis and 
incumbent on it, spongy pubescent but almost devoid of hairs; no cheeks; ocellar triangle not elevated, 
ocellar and vertical bristles reduced in size so as to be almost invisible. Thorax not much elevated, 
entirely without bristles, scutellum with six or eight short marginal hairs, metapleura bare, at most 
with a couple of microscopic hairs. Abdomen slender, longer than the thorax, depressed, hairs short 
and sparse, a transverse series of small round pits present at the base of the second segment; pygidium 
terminal globular, with a flat dorsal valve and moderately large convex lateral valves, penis short and 
thick, no projecting appendages, abdomen of the female tapering to the end styles. Legs slender, 
simple, rather sparsely provided with fine pubescence, but entirely devoid of bristles; pulvilli small. 
Calypteres with a straight edge and reduced fringe. "Wings long and slender, anal angle obtusely 
rounded, not prominent, costa extending around the entire wing, no basal bristle, auxiliary vein 
straight, distinct, ending in the costa just before the middle of the wing, a very faint stigmal spot, 
third vein forked, basal cells elongate and equal, discal cell rather narrow, often pointed apically, 
sections of the fourth vein proportioned 0.8: 0.2: 1: 1.5, of the fifth vein, 1.4 : 0.5 : 1 : 1.2, anal 
crossvein abruptly recurved and fused with the under side of the anal cell but not reaching back to the 
middle of the cell, anal vein evanescent. 
Type species : H. Mabele (Pl. 7, Fig. 61), by original designation. This species occurs 
sparingly in the deep shade of fir forests, flying close to the ground. 
Geographical distribution. 
1. H. Mabele, Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 277, f. 98[1902] Idaho. Montana. 
(Ragas); Ent. News, Philad. Vol. 17, p. 377, fig. (1906). — PI. 7, 
Fig. 61. 
2. H. sanduca, nov. sp. (1). California. 
(1) Hesperempis sanduca, nov. sp. — Male. Length 2.6 mm. Entirely pale yellow except the eyes and the 
last two joints of the hind tarsi, not pollinose but only subshining, hairs and bristles yellow. "Third joint of the antenne 
bluntly conical, scarcely tapering, twice as long as wide and six times as long as the brown style. About fifteen short 
dorsocentral hairs, six scutellaw; metapleure) with two microscopic hairs. Hairs of the abdomen rather long. Legs 
simple, bristleless. Wings clear hyaline, veins weak and yellow, second posterior cell sessile, the vein between the discal 
and the third posterior cells angulate at two-thirds its length and sending a short spur into the discal cell, anal vein nearly 
obsolete, its base continuous with the under side of the anal cell. 
Type, San Francisco, California, collected by Charles Fuchs. A female from Forest Grove, Oregon, June 2 
(F. R. Cole). ^ 
