77. 
78. 
79. 
80. 
81. 
(75) 
82. 
83. (81) 
84. 
85 
86 
. (73) 
. (60) 
87. 
HORSEFLIES OF THE SUBFAMILY TABANINAE 
Key to Nearctic Females of Tabanus—Continued 
Height of frons not more than four times basal width, with 
parallel sides; basal callus large, very shiny, and usually 
FECHA Z MLN OTs SUT Ceres ee ye Sees weer ates Se 
Height of frons not less than four and one-half times basal 
width and usually somewhat widened above; basal callus 
not so large and usually narrowed above_---____--________ 
Basal portion of third antennal segment with no dorsal excision 
endymion Osten Sacken, p. 108. 
Basal portion of third antennal segment distinctly excised above_ 
Entirely orange brown, including wing, the median triangles 
faint and not arising from bands on hind margins of tergites 
johnsoni Hine, p. T9. 
OrhenwaASeReeol ore Ges see ie aa Pet rea Pe ee a: _ peers et A 
Abdomen orange brown, with yellowish bands on hind margins 
of tergites that expand into rather large median triangles 
cheliopterus Rondani, p. 109. 
Abdomen uniformly dark reddish to nearly black, the small, 
median, white triangles not arising from bands___-----_~- 
Abdominal white spots very small, as broad as long_-_______~- 
Abdominal white spots larger, considerably longer than broad 
recedens Walker, p. 110. 
Base of third antennal segment with a prominent, forward- 
DEOTEELINE, processi2 8 sk oe! imitans Walker, p. 86. 
Dorsal angle of third antennal segment not projecting forward 
imitans var. excessus, new variety, p. 87. 
Cell R; closed or strongly narrowed apically ________-----__-_-- 
CONES MIVAGOCWODOM as -ae Sl Sete ee be ie ee ee 
Legs uniformly orange brown___________-_ nefarius Hine, p. 111. 
Herr ores lol aie kee eso Vt Oe rer giganteus Degeer, p. 84. 
Annulate portion of third antennal segment shorter than basal 
portion, the latter scarcely excised above; usually less than 
emi -melengih 22) 2 a ee coarctatus Stone, p. 111. 
Annulate portion of third antennal segment longer than basal 
portion, the latter with a rather pronounced dorsal excision ; 
NSA HOVeL aim ImMn ONS 2-2 fo eS 
Costal cell yellow; frons about six times as high as basal width 
and conspicuously widened above; antenna entirely orange 
brown; hair of hind tibia predominantly brownish 
turbidus Wiedemann, p. 112. 
Costal cell nearly hyaline; frons about four and one-half times 
as high as basal width and not so distinctly widened above; 
basal portion of third antennal segment with considerable 
black; hair of hind tibia mostly pale yellowish 
equalis Hine, p. 113. 
Frons moderate in width; pale abdominal triangles distinct; at 
least middle femur brownish; cell Rs narrowed toward 
margin but rarely closed; wing nearly hyaline but for 
SSG) iyo eee RESIN NE ae sulcifrons Macquart, p. 114. 
Frons very narrow, slightly widened above; pale abdominal 
triangles usually not so distinct as the larger black mark- 
ings; all femora black; cell Rs closed; anterior half of wing 
distinctly yellowish brown___-abdominalis Fabricius, p. 116. 
Fureation with a small spot; (more than 15 mm long, yellow- 
HSS TAIT" Wes) ene acutus (Bigot), p. 117. 
Murcatione wat houtta “Spots fa) ae ee 
Eye with a single purple band; frons nearly parallel-sided ; 
annulate portion of third antennal segment usually longer 
than basal portion; costal cell colored, sometimes faintly ; 
prescutal lobe usually concolorous with rest of mesoscutum__ 
Eye with two purple bands; frons somewhat widened above; 
annulate portion of third antennal segment shorter than basal 
portion; costal cell as hyaline as rest of wing; prescutal 
lobe usually paler than rest of mesoscutum_____--__________ 
43 
(7 
78 
79 
80 
82 
83 
84 
87 
88 
