342 



AN ECONOMIC ENTOMOLOGY. 



Fig. 390. 



oil of pennyroyal, and sweet oil— must be resorted to for man, 

 while fish oil, with an admixture of crude carbolic acid or creo- 

 sote, will be found effective for animals. Smudges are often 

 used where buffalo-gnats are abundant, and the 

 stock soon learn that in or near the smoke ex- 

 emption from attack may be secured. Where 

 the water of infested streams 

 is deep, undue multiplication 

 is frequently chargeable to an 

 accumulation of logs or other 



IIS ""^"^Mt^^^^-^ material at certain points, af- 



''^81 rf^^v^ fording suitable locations for 



^ * '""^ the development of the gnat 



larvae. In such cases much 

 good may be accomplished 

 and sometimes practical ex- 

 emption may be secured by 

 cleaning out the streams and 

 thus destroying the breeding- 

 places. Stationary rafts of logs 

 should not be allowed, and the 

 surface should be kept as free as possible of anything to which 

 the larvae can attach themselves. 



The * ' horse-flies, ' ' or Tabanidcs, comprise another set of 

 troublesome creatures, of medium or large size. They have 

 short, broad heads, enormous eyes, and short, though many- 

 jointed, feelers. The abdomen is oval, a little flattened, and the 

 body is convex and powerful. The mouth parts are well 

 developed, consisting of a series of five sharp-pointed lancets so 

 rigid that they readily pierce the skin and draw blood almost as 

 soon as they touch. These flies frequent woods or the edges of 

 woodland, sometimes low meadows or marshy places, and occa- 

 sionally prove serious pests to stock. They are often trouble- 

 some in woody roads, because with three or four of the large 

 black flies buzzing about, horses may be driven almost frantic. 

 Similar species occur in great numbers along the sea-shore, 

 where they are known as "green-heads." In some localities 

 they are known as "deer-flies," and some are called "golden- 

 eyed flies," having the eyes more or less banded or striped 



Larva of buffalo- 

 gnat. 



Pupa of buffalo-gnat . 



