TWELVE] OUR RIVAI.S—THE INSECTS 
as fast as they appear. Fortunately for us, the 
forest worm very soon finds its parasitic enemies, 
or it would absolutely overwhelm us with its: multi- 
tude. The tent caterpillar also has its insect ene- 
mies, so that it is very migratory in its appearance. 
Neither of these pests are generally found more 
than two years in succession in the same locality, 
at least in force. ‘There must be no dallying with 
them, however, for if allowed to get well in- 
trenched they will devour our orchards and 
even our lawn trees inside of two weeks. Not 
only is our fruit crop destroyed, but the trees are 
so devitalized by two years of feeding that 
many of them will die outright. I have seen 
large belts of forest trees killed by forest worms 
as if by fire. 
Canker worms, or, as they are generally called, 
“measuring worms,” are of two kinds, the spring- 
feeders and the autumn-feeders. The early sort 
must be shaken from the trees, and bands of tarred 
cotton put about the trunks to prevent their climb- 
ing up again. As arule, our winter birds will take 
care of the late brood, if they are encouraged. Cut 
worms are not often on hand in serious numbers, 
but when they are wind your trees with cotton bat- 
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