HORSEFLIES OF THE SUBFAMILY TABANINAE 107 
Described from specimen collected at Orlando, Fla., June 7, 1931, 
by D. T. Ries. 
Type.—Female, collection unknown. 
Type locality. Kentucky. 
Distribution.—Connecticut to Florida. March 29 (Paradise Key, 
Fla.) to August 19 (Hilliard County, Fla.). In the United States 
National Museum, 40 females, 3 males, 
It is extremely doubtful that this is the same as 7’abanus exaestwans 
Linnaeus from Surinam or that melanocerus occurs in Central Amer- 
ica, as has been suggested by Osten Sacken and Krober (7/7). 
TABANUS TRIJUNCTUS Walker 
(Fig. 49, A) 
Tabanus trijunctus Walker, List of the Specimens of Dipterous Insects in the 
Collection of the British Museum, pt. 5, sup. 1, p. 182, 1854; Osten Sacken, 
Mem. Boston Soc. Nat. Hist. 2 (pt. 4, No. 4) : 482, 1876; Mosier and Snyder, 
Ent. Soc. Wash. Proc. 20: 118-126, 1918; Philip, Bull. Brooklyn Ent. Soc. 
31: 195, 19386. 
Medium sized; blackish, with a median row of broad white triangles on 
abdomen; venter black, with prominent white bands; wing orange brown, with 
a distinct spot at furcation; fore tibia unicolorous. 
Figure 49.—Antenna, front view of head, and palpus of (4A) Tabanus trijunctus and (B) 
T. endymion. 
Female.—Length 15-21 mm. Eye bare, purple, with two green bands. Whole 
head grayish yellow; frons about three and one-half times as high as width at 
base, slightly widened above; basal callus black, shiny, higher than wide, touch- 
ing eyes at bottom only; median callus black, spindle shaped, joined to basal 
callus; subeallus quite flat. Antenna orange brown, the first segment slightly 
darker; second with a strong dorsal process; third rather slender, with a 
prominent dorsal angle and deep excision; annulate portion shorter than basal 
portion. Clypeus and genae with yellow hair. Second palpal segment slender, 
dark orange brown, with a mixture of short black and orange hair. 
Mesonotum dark reddish brown, with yellowish pollen and short black hair; 
prescutal lobe and middle of pleura with dense black hair; yellow hair above 
and below wing base and around margin of scutellum. Wing strongly suffused 
with orange brown except at apex and along hind margin, where it is sub- 
hyaline; furcation and cross veins distinctly margined with brown; cell Rs 
strongly narrowed apically. Legs orange brown, with orange hair, except coxae, 
which are yellowish gray, with black hair, fore femur, which is black, with 
black hair, except at apex, and apex of fore tibia sometimes, and tarsi always, 
which are darkened; hind tibial fringe well developed, concolorous with tibia. 
Abdomen above black, with considerable orange brown on sides of tergites 1-3; 
tergites 1-5 with narrow, yellowish-white, posterior bands which widen to form 
a row of prominent median triangles and also widen slightly laterally; sternites 
black, with prominent white bands on hind margins. 
Male.—Kye somewhat flattened above, the areas of large and small facets dis- 
tinctly differentiated, the small facets extending along upper margin of eye; 
palpus black, with black hair. Rest of coloration much as in female, but no 
trace of white on fifth tergite. 
