RELATION TO OTHER ANIMALS 



169 



The Tabanidce, including those forms known as 

 "horse-flies," "deer-flies," "green-heads," "breeze-flies," 

 " golden -eyed flies, " and perhaps a number of other pop- 

 ular terms, are all much larger species, some of them 

 among the largest in the order. They are all blood 

 suckers in the female and feeders on nectar or other 

 plant secretions in the male. In fact the males are 

 as shy and retiring as the females are bold and obtru- 



Fio. 74. Black horse-fly, Tabanus atratus: a, larva; b, pupa; c, adult. 



sive, and very little is actually known of them and their 

 habits. The popular names are all applied to the fe- 

 males and are chiefly based on their habits or appear- 

 ance. The "horse-flies" are among the largest of the 

 species some of them great massive fellows an inch 

 or more in length; black, blue, brown or striped with 

 yellow; sometimes covered with a bluish, whitish or 

 golden bloom. They attack horses or cattle in their 

 districts and so stout and short are their horny lancets 

 that blood comes almost as they settle. High-strung, 

 thin-skinned horses are sometimes driven frantic by 



