276 NATURAL HISTORY OF THE FARM 
and filled with water by 
the rains, often furnish 
the chief supplies of mos- 
quitos to a whole neighbor- 
hood. Few are reared in 
open water inhabited by 
fishes; for the fishes eat 
them. The smaller the pool, 
the more likely it is to 
contain mosquito larvae. 
The larvae take air at the 
surface of the water, but 
swim down below to find 
forage or to escape danger. 
NC dime em Many species are adapted 
to the drying 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-lived, and run 
through quite a number of generations in a single summer; 
these develop in vast numbers when a rainy season main- 
tains an abundance of little pools. 
Black-flies (Family Simuliidae) develop in running water, 
and are most troublesome about woodland streams. The 
habits of the larvae, which live 
upon stones, have been discussed 
on pages 36 and 37. When there 
are no stones in the streams, larvae 
may be found 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’sedge. The adults (fig. 117) 
love the sunshine, and their biting 
is troublesome only by day. Fig, U8 A, Needy (irom the 
