5© OHIO STATE ACADEMY OP SCIENCE. 



TABANUS cosTALis Wiedemann. 



Length 12-14 mm. Palpi yellowish, antennae brownish with the 

 annulate portion darker ; thorax including the scutellum uniformly grayish 

 yellow pollinose; legs largely black, base of front tibiae and the middle 

 and hind tibiae except at apex yellowish ; wings hyaline with the costal 

 cells yellowish, veins yellowish; abdomen above alternately striped with 

 black and grayish yellow. 



Female: Frontal callosity black, above with a very much narrowed 

 prolongation the part of which adjacent to the callosity is sometimes 

 obliterated leaving the upper part as a separate spot. 



Male : This sex is much like the female and easily associated with 

 it, but there is a tendency toward obliteration of the distinct markings 

 of the abdomen, the black of the female is replaced by brownish and 

 the stripes may blend so that the whole base of the abdomen is prac- 

 tically one color. 



Habitat : Common all over Ohio. 



This species may be confused with nigrovittatiis, sagax and 

 fulvulus, all of which have the yellowish costal cells. The last 

 two are usually larger than costalis, and the spots on the sides 

 •of the abdomen above are not contiguous ; the former has the 

 apex of the third tibia reddish, while costalis has the same part 

 black. So far nigrovittatus is known from the Atlantic coast only. 



The green-headed fly, as costalis is called, is one of our worst 

 stock pests. It is most abundant during August, when a large 

 number of other annoying flies are numerous. 



TABANUS EPiSTATus Ostcn Sacken. 



Length 14-16 mm. Eyes pilose, ocelligerous tubercle present; thorax 

 black with rather prominent gray stripes ; wing hyaline with extreme 

 base, costal cells, and veins brownish, abdomen broadly reddish on the 

 sides. 



Female : Subcallus often although not always denuded ; palpi dis- 

 tinctly thickened and rather short, front gradually widened above, 

 frontal callosity small, shining brown, rounded above, and separated 

 from a linear shining spot above it by a pollinose interval. Legs brown, 

 femora lighter than the other parts. 



Male : Subcallus not denuded in the specimens before me, head 

 rather small, eyes distinctly pilose; palpi short and thick. 



Habitat : Sandusky ; taken in the tall grass on the border 

 of a marsh July 6th. 



This species is very close to afUnis, but easily separated from 

 it by the enlarged palpi. The palpi in afUnis are long and slender. 



The color of the abdomen is variable, in some specimens 

 there is a distinct black middorsal stripe, but in others this stripe 

 is more or less broken up by the encroachment of the reddish. 



