TWO-WINGED INSECTS. 297 
Fig. 230. 
They are generally most troublesome in warm climates, 
and in the tropics they are present throughout the year. 
But there are some cold countries in which, during their: 
brief but hot summers, they are not only extremely an- 
noying, but occasionally very destructive. This is the 
case with parts of Russia, both in Europe and in Asia. 
Even such animals as horses, oxen, sheep, goats, and 
hogs, are so severely stung by them as to die, some meet- 
ing their death by drowning, having run into water to 
escape the swarms of their small but formidable enemies. 
At some periods it seems in that country to be the grand 
business of life to devise and put in execution expedients 
for guarding man and beast against these insects. 
N 2 
