78 DIPTERA OF MINNESOTA. 



in the case of aquatic forms. Pine woods, too, seem to attract them. 

 Some forms of larvae are said to live in rotten wood. The larvae 

 are always carnivorous, feeding on snails, or the early stages of insects, 

 thus offering something of a compensation for the mischief caused 

 by them as adults. Not only are the attacks of Tabaiiids exasperating 

 to both man and beast, but it is quite possible, even probable, that they 

 may transmit disease, by biting a well animal after having fed upon 

 the blood of some infested creature. They are probably active agents 

 in distributing the disease known as "anthrax." 



The writer was appealed to for help last summer by a mail carrier 

 in the northern part of the state, who had to discontinue carrying mail 

 on account of the attacks of Tabanidae upon his horses. Nets or light 

 covers are, of course, a protection, particularly the latter. 



There are in the entire world, according to Williston, about 1,400 

 or over (probably at least 1,500) known species belonging to this 

 family. Over 150 of these are American. Tabanus alone, a very 

 common genus, has more than 100 species in America, and there are 

 at least 50 North American species of the genus Chrysops. Rein- 

 wardt's Breeze Fly (see illustration) is very common in our prairie 

 country. Dr. Lugger speaks of them as so numerous on a window 



Fig. 67. Chrysops aestuans. Lugger. 



pane in a small rural station on the prairie as to obscure the light, and 

 upon the bench below the window he counted 2,117 Ai^s. 



