276 



NATURAL HISTORY oF THH FARM 



-^'N 



11: 



The buffalo-gnat {Sitnulium 



fecuarum, after Garmanj. 



and filled ^vith water In' 

 the rains, often furnish 

 the chief su])])lies of nws- 

 (juitos to a whole nei^^hbor- 

 hood. Few are reared in 

 o])en water inhabited by 

 fishes; U)r the fishes cat 

 them. The smaller the pool, 

 the more likely it is to 

 contain mosquito lar\'ae. 

 The larA'ae take air at the 

 surface of the water, but 

 swim down below to find 

 forage or to escape danger. 

 Many species are adapted 

 to the dr\ing up of their 

 native pools, and live on (usually in the egg stage) in 

 absence of water, and come on again and fly and sing and 

 bite at their proper seasons. Some are short -li\-ed, and run 

 through quite a number of generations in a single summer; 

 these de\elop in vast numbers when a rainy season main- 

 tains an abtmdance of little pools. 



Black-flies (Family Simuliidae) develop in nnming water, 

 and are most troublesome about woodland streams. The 

 habits of the larvae, w^iich live 

 upon stones, ha\e been discussed 

 on ])ages 36 and 37. When there 

 arc no stones in the streams, lar\'ae 

 may be foimd hanging to sticks 

 and to grass blades that trail in 

 the edge of the current. The eggs 

 are laid on logs and stones at the 

 water's edge. The adults (fig. 1 1 7 ) 

 love the sunshine, and their biting * 



.11 1 u J Fi<;- 11^- A horse-fly Cfrom the 



IS troublesome only by day. u. S. Bureau of Entomology; . 



