(.anadian Fnrcs'rif Journal. Mai;, 1918 



1G73 



LAKF OF THC WOODS 



Some Notes on the Control of Foliage 

 Eating Insects Under Forest Conditions 



By John D. Tothill 



In Charge of Natural Control Investigation, Entomological 

 Branch, Department of Agriculture 



How many readers have wit- 

 nessed an insect outbreak in the 

 woods? Swarms of caterpillars; 

 trees for miles stripped of nearly 

 all their greenery; and a sense 

 of depression like that produced 

 by a forest newly swept by fire! 

 Outbreaks of this character occur 

 at irregular intervals on most of 

 our valuable forest trees. At such 

 times the losses involved are often 

 very great. 



About thirty years ago, for instance, 

 an outbreak of saw flies occurred on 

 the larch or tamarack in New Burns- 

 wick. The insects were present in 

 such numbers that practically the 

 entire tamarack stand was killed 

 and since that time the tamarack 

 swamps have been praclicallv unpro- 

 juctive. In recent vears the same 



forest area has been exposed to an 

 outbreak of the spruce budmoth. 

 This has resulted in the weakening 

 and death of a large proportion of 

 balsam fir (Abies balsamea) now of 

 great value for the production of 

 pulp. In this case the loss involved 

 will probably be greater than the 

 sum total of fire damage for the 

 past fifty years in the forests of the 

 same Province. Other cases could 

 be cited for all our Canadian forest 

 regions, but these two cases will 

 serve perhaps to indicate how great 

 are the losses often resulting from 

 outbreaks of forest insects. 



Camping in woods rendered des- 

 olate by an insect outbreak and 

 far from human habitation, one 

 is faced with the apparent hope- 

 lessness of the situation. Cre- 



