HORSEFLIES OF THE SUBFAMILY TABANINAE 97 
from it of about equal length and about one-fourth width of frons, scarcely 
narrowed at junction with basal callus; vertex flat, completely pollinose; sub- 
callus pale yellowish gray, nearly flat. Antenna dark reddish brown to black, 
the first two segments with short black hair; first segment distinctly widened 
apically ; second with a slender dorsal process; third with a prominent dorsal 
angle, the dorsal excision distinct but not very deep; width of basal portion 
and length of annulate portion each about three-fourths length of basal por- 
tion. Clypeus and genae below antennae pale gray, with mostly white hair. 
Second palpal segment pale yellowish, with a mixture of short black and white 
hair, moderate in thickness at base, gradually tapering to a sharp apex. 
Mesoscutum brown, with five distinct light-gray lines in usual pattern; 
prescutal lobe reddish gray, with black hair below; scutellum with grayish 
pollen discally, reddish around margin, the whole with pale hair. Pleura, 
sternum, and coxae gray tinged with reddish and with gray hair. Wing nearly 
hyaline except for deep-yellow costal cell and infuscated spots at cross veins 
and fureation; cell Rs somewhat narrowed apically. Legs dark brown to black 
except for basal half of fore tibia and basal three-fourths of middle and hind 
Ficure 43.—Antenna, front view of head, and palpus of (A) Tabanus trimaculatus and 
B) T. molestus. 
tibiae, which are white; hair of legs largely white except for dark portions 
of tibiae and tarsi. 
Abdomen black or reddish brown dorsally, with a prominent, median, white 
triangle on each of tergites 3-5, that. on 3 not reaching anterior margin; some- 
times tergite 2 bearing a pair of small, pale, oblique spots on each side of mid- 
dle; lateral margin of each tergite with white pollen and hair; venter gray, with 
a broad, dark-brown, median stripe. 
Male.—Areas of large and small facets of eye sharply differentiated, the 
former extensive but separated from hind margin of eye by a narrow extension 
of the small facetted area; in dried specimens the area of large facets usually 
yellow, with a broad dark band across it. Antenna and legs somewhat paler 
than in female, the rest of coloration as in female. 
Type.—Female, collection unknown. 
Type locality—North America. 
Distribution.—Minnesota and New York south to Texas and 
Georgia. June 9 (Mount Vernon, Va.) to August 20 (a Crescent, 
Minn.), In the United States National Museum, 32 females, 9 males. 
TABANUS MOLESTUS Say 
(Fig. 43, B) 
Tabanus molestus Say, Jour. Acad. Nat. Sci. Phila. 3: 31-82, 1823; Wiedemann, 
Aussereuropaische zweifitigelige Insekten, v. 1, p. 125, 1828; Say, Complete 
Writings, LeConte ed., v. 2, p. 53, 1859; Osten Sacken, Mem. Boston Soc. 
Nat. Hist. 2 (pt. 4, No. 4): 488-439, 1876; Hine, La. Agr. Expt. Sta. Bull. 
93 : 52-53, 1907. 
Atylotus tenessensis (sic) Bigot, Mem. Soe. Zool. France 5: 660, 1892. (New 
synonymy. ) 
Medium sized; dark brown to black, with large, gray, median triangles on 
abdomen, that on second tergite decidedly smaller than those on third and 
fourth; scutellum with white pollen and pile; fore tibia nearly uniformly dark 
brown. 
38521°—38——7 
