150 MISC. PUBLICATION 305, U. S. DEPT. OF AGRICULTURE 
Type—A male, in the Vienna Museum. 
Type locality —Kentucky. 
Distribution.—Minnesota to Quebec and Maine and south in the 
east to Georgia. June 5 (Southern Pines, N. C.) to August 28 (Hop- 
kins, Minn.). In the United States National Museum, 42 females, 21 
males. 
Williston describes the eyes of Z’abanus sodalis as being bare. In 
every other respect the description fits 7. trispilus perfectly, and 
since the pile is very short and fine in this species and easy to over- 
look, there is no reason for doubting the synonymy. 
TABANUS ILLOTUS Osten Sacken 
(Fig. 72, B) 
Tabanus illotus Osten Sacken, Mem. Boston Soc. Nat. Hist. 2 (pt. 4, No. 4) : 469- 
470, 1876; Hine, Ohio Nat. 5: 238, 1904; Cameron, Bull. Ent. Research 17: 
28-29, 1926; Philip, Minn. Agr. Expt. Sta. Tech. Bull. 80: 32-83, 107-108, 
1981. 
Rather small; blackish, with round, grayish, sublateral spots on tergites 2 and 
3 and small median triangles, the spots behind evanescent; palpus stout. 
Female.—Length 12-14 mm. Eye with dense, short pile, purple, with three 
green cross bands. Frons grayish tinged with yellow brown, three and one-half 
times as high as width across basal callus, distinctly widened above; a distinct 
ocellar tubercle; basal callus shiny brown to black, nearly square; median callus 
rather short and narrow, sometimes separated from basal callus; subcallus gray. 
First two antennal segments orange brown, with black hair; third orange bas- 
ally, tinged with black above, the annulate portion black; dorsal angle short, 
obtuse, and dorsal excision moderate; annulate portion short, stout, about equal 
in length to greatest width of basal portion. Clypeus and genae gray, with 
nearly white hair. Second palpal segment stout at base, cream colored, with 
short black hair. 
Mesonotum nearly black, with gray lines in usual pattern; prescutal lobe and 
region around wing reddish. Pleura, sternum, and coxae mostly gray, with 
whitish hair. Wing hyaline, with dark-brown veins, the venation normal; faint 
brown spots at furcation and cross veins. Femora gray; tibiae reddish brown, 
with pale hair, darker apically; hind tibial fringe slight, largely white; tarsi 
dark brown to black. 
Abdomen above black, with three rows of gray spots, sometimes tinged with 
reddish ; a Small, but distinct, narrow triangle on second tergite and very faint 
spots on others; the sublateral row consisting of a large round spot on second 
tergite usually not touching any margin, a somewhat smaller round spot on third 
tergite, and very faint spots posterior to these; venter black, often with con- 
siderable areas of reddish brown. 
Male.—Facets of eye nearly uniform in size, the larger facets not sharply 
differentiated from the smaller; first antennal segment gray; second palpal 
segment stout, rounded at tip. Legs darker than in female, the hind tibia 
entirely black. Abdomen with very small median spots, the sublateral spots on 
tergites 2 and 3 large, orange brown, confluent, but narrowly separated from 
lateral margin. 
Type—A specimen from Hudson Bay Territory, 1 of 10 cotype 
females in the Museum of Comparative Zoology, No. 4027, herein 
designated as the lectotype. One of the 10 cotypes is actually Z'a- 
banus nivosus Osten Sacken. | 
Type locality—Hudson Bay Territory. 
Distribution.—Alaska to Quebee and south to Washington, Iowa, 
and New York. May 28 (Point Pelee, Ontario) to July 27 (Aweme, 
Manitoba). In the United States National Museum, 21 females, 4 
males, 
