HOW THE FOREST IS GUARDED 103 



Brought over from Europe for experiment purposes 

 about forty years ago they escaped by accident and 

 were not heard of for some time. When their activities 

 near Boston were noticed an appropriation was made 

 for a few years but against the recommendations of 

 experts this appropriation was discontinued for about 

 five years because they appeared to be extinct. In 

 reality two or three years' more work would have exter- 

 minated them completely. With the cessation of pre- 

 ventive measures the moths increased rapidly and as 

 a consequence they spread from Massachusetts to prac- 

 tically all of the New England States. In Massachusetts 

 alone nearly $1,000,000 per year is spent by the State, 

 Federal Government, and private individuals to con- 

 trol these destructive insects. 



Leaf-eaters like the larvae of the gypsy and brown- 

 tail moths, the elm leaf beetle, etc., can be killed by 

 poisoning their food. A solution of lead arsenate is 

 sprayed upon the leaves and the caterpillars die by the 

 thousand after eating the leaves. However, the difficulty 

 and expense of spraying thousands of acres of wood- 

 land is at once apparent and unless the natural enemies 

 multiply and can take care of a large part of the 

 annual crop of these pests, neighboring States must 

 certainly be invaded by hungry armies of insects. By 

 creosoting the egg masses, by removing trees to which 

 they are especially partial and by breeding and 

 liberating parasites it is hoped to keep them in check. 



Fungi. The harmful effects of fungus disease are 

 noticed both on living and dead timber. Those found on 

 dead timber are called "saprophytes" and are not 

 especially dangerous. Of the parasitic fungi those 

 that attack living trees one. of most importance at 

 present is the chestnut bark disease Endotkea para- 



