THE WHITE-PINE WEEVIL 



199 



Influence of Density on the Extent of Weevil Injury 



In open stands where the crowns are all free the trees are all equally 

 subject to attack, but in the denser stands the percentage of trees suit- 



9000 



80O0 



7000 



6000 



5000 



4000 



3000 



2000 



1000 



LOSS KR TUCK IN FCKT 



FiC. 5. — Relation of the loss per tree in height growth to the density of the stand 



able for the development of the weevil becomes smaller, while in very 

 dense stands the injury may be reduced to practically nothing. 



