1910.] Distribution of the Large Larch Saw-fly. 989 



would reveal the presence of the saw-fly in the N.W. and 

 S.E. of Scotland as well. 



Remedial Measures. — It has already been noted that in the 

 United States no successful remedy has been discovered 

 against the saw-fly, and the diminution of the intensity of 



1/ 



Loch 



Loch 



ft 7 Call; 



1 



o A.beTfeldy 



4- oOu-nkeld J. 1 



■ndCT 



a am is J^-' 





y 



• (( 



^ 0 Mauchlh 

 0l\yy 



/l(< A 



; n 4 



■'/JJaCxi Tvan 



w 



e 



o OoTtifTi es 



buTgh 



Galashiels 



-4 



New foTi StewarS: 



^^^^ 



y o Castle OooLlas J 



oCa-rlisle 



Fig. 3. — Distribution of the Large Larch Saw-fly in Scotland. 



( The small numerals refer to the intensity of attack. ) 



its attack from time to time has been due solely to natural 

 causes. 



The difficulty of treatment is due to a number of reasons. 

 They are briefly : — • 



1. The nature of the life-history of the insect. The cater- 

 pillar winters in a cocoon under grass or moss, where it is 



