HORSEFLIES OF THE SUBFAMILY TABANINAE 119 
TABANUS CAYENSIS Fairchild 
(Fig. 56, A) 
Tabanus cayensis Fairchild, Florida Ent. 18: 58-54, 1935. 
Small; abdomen above with a parallel-sided, gray, median stripe superim- 
posed on a broader black stripe; costal cell brown; frons very broad. 
Female.—Length 9 mm. Hye bare, greenish, with a single, diagonal, purplish 
band. Frons grayish, about two and one-half times as high as wide, with par- 
allel sides; basal callus shiny chestnut brown, about as high as wide; median 
callus oval, narrowly connected with basal callus; vertex bare, flat, the denuded 
area running down eye margin a short distance and connected medianly with 
median callus; subcallus grayish. First two antennal segments yellowish 
brown, with black hair; basal portion of third orange, darkened apically, the 
annulate portion black ; basal portion slender, with a short, obtuse, dorsal angle; 
annulate portion nearly as long as basal portion. Second palpal segment white, 
with scattered black hair, scarcely swollen basally and with rather blunt apex. 
Ficgurp 56.—Front view of head and palpus of (A) Tabanus cayensis and antenna, front 
view of head, and palpus of (B) T. fuscicostatus and (C) T. nigrovittatus. 
Mesonotum black, with grayish pollen, the humeral and prescutal lobes yel- 
lowish brown. Pleura, sternum, and coxae gray tinged with brown. Wing 
subhyaline, the veins narrowly margined with brown and costal cell distinctly 
brown. Legs blackish except the yellowish basal half of fore tibia and all of 
middle and hind tibiae. 
Abdomen above dark grayish, with a rather broad, gray, median stripe, large 
yellowish spots sublaterally on tergites 1-4, those anteriorly reaching to sides 
of tergites and contiguous with one another, and narrow, yellowish, posterior 
bands; venter yellowish basally, darker apically. 
Male.—Unknown. 
Type.—Female, Museum of Comparative Zoology No. 20134. Para- 
type, United States National Museum No. 50803. 
Type locality.—Stock Island, near Key West, Fla. 
Distribution.—Monroe County, Fla., July 1. In the United States 
National Museum, one female. 
TABANUS FUSCICOSTATUS Hine 
(Fig. 56, B) 
Tabanus fuscicostatus Hine, Ohio Nat. 7: 24, 1906; La. Agr. Expt. Sta. Bull. 
93: 49-50, 1907. 
Rather small; brown, with a pale dorsal stripe and usually faint sublateral 
spots on abdomen; costal cell dark. 
Femaie.—Length 10-18 mm. Hye bare, green, with a single, diagonal, purple 
band. Frons three and one-half to four times as high as wide, nearly parallel 
sided, yellowish brown; basal callus shiny yellowish brown, square or slightly 
higher than wide, narrowly separated from eyes; median callus small, wrinkled, 
rarely joined narrowly to basal callus; subeallus concolorous with frons. First 
two antennal segments yellowish, with black hair; third orange, the annulate 
portion slightly darker; dorsal angle obtuse and excision shallow; annulate 
portion slightly longer than basal portion. Clypeus and genae whitish, with 
white hair. Second palpal segment slightly swollen basally, creamy white, with 
a mixture of black and concolorous hair. 
Mesonotum blackish brown, with brownish-gray lines in usual pattern; rest 
of thorax gray, with whitish hair. Wing hyaline, the costal cell and stigma 
brown; veins brown, the venation normal. Legs yellowish brown, the apical 
half of fore tibia and the tarsi darker; hind tibial fringe black. 
