102 TEE BOOK OF FORESTRY 



egg masses of the leaf -eating beetles or destroying broods 

 of the tent caterpillars. 



Insects. While the effects of insects are not often 

 heard of, nevertheless, year in and year out an enormous 

 amount of damage is done to our forests and shade trees 

 by these winged pests. In the seventies the larch sawfly 

 threatened to exterminate this valuable timber tree 

 from our Northern forests. The spruce bark beetle has 

 taken a heavy toll from time to time in the New Eng- 

 land States; the Western pine beetle for several years 

 threatened the splendid yellow pine stands of the Black 

 Hills. Even now we hear of the white pine weevil and 

 its destructive effect upon young pine plantations; the 

 ravages of the elm leaf beetle and the enormous loss 

 caused, largely in the New England States, by the 

 gypsy and brown-tail moths. 



Remedies for these agencies are not always easy to 

 discover. Bark beetles can best be exterminated by 

 felling the trees and burning the bark or else soaking 

 the infected logs in a stream. This can be done quite 

 readily where the logs are ordinarily floated to the mill, 

 by timing the cutting according to the development 

 of the insect. 



For the white pine weevil several cures are suggested. 

 Cutting and burning the withered leaders of the young 

 pine trees during June will kill the grubs but at the 

 same time it may kill some parasities which have been 

 preying upon the larvae. The latest remedy suggested 

 is to cut off the leader which is dying and by putting 

 it in a barrel covered with a fine screen, the parasites 

 can escape, and will prey further upon the pest. 



Suppression of the gypsy and brown-tail moths is a 

 job that the New England States assisted by the 

 National Government are finding well-nigh impossible. 



