152 Bulletin 234. 



a resin-oil wash. Adams treated about forty trees in Buffalo with a resin- 

 oil wash (5 pounds resin dissolved and i gallon raw linseed oil poured 

 in) with no satisfactory results. As the insect infests all parts of the 

 tree, from branches half an inch in diameter to the trunk, it would be 

 difficult to so cover the bark as to allow no place for egg-laying, or to 

 put on such a coating as to prevent the exit of the beetles. I doubt the 

 practicability and effectiveness of such methods against this birch borer. 



Some have tried to save their trees by cutting out the top branches 

 that were dead or dying, but in every case the trees finally succumbed. 

 This pruning may sometimes delay the inevitable death of the tree for a 

 year or more. / doubt if a tree can be saved after it is once infested to 

 tlie extent that the top branches are dying. Better sacrifice the n'hole 

 tree at once and thus prevent the spread of the pest to neighboring trees. 



This brings me to the only practicable and effective method of deal- 

 ing with this borer. That is the heroic one of cutting down and burning 

 the infested tree, trunk and branches, before May ist, thus destroying 

 the whole crop or generation of borers in their hibernating quarters under 

 the bark. As soon as the top branches are killed (as shown in the frontis- 

 piece and in Fig. 34), do not delay a moment, but cut and burn the tree, 

 as its death is inevitable within a year or two. 



But this is much more easily said than done, as any one can testify 

 who has tried to persuade owners of private grounds or park authorities 

 to apply the method in time. Sentiment and the forlorn hope that the 

 tree may revive or last a few years more, often results in an infested tree 

 remaining as a leafless eyesore on the landscape for a year or more after 

 it is dead and all the beetles have been allowed to emerge and spread to 

 other trees. It seems to be almost impossible in many cases to get indi- 

 viduals or city authorities to act promptly. Often after one succeeds in 

 getting an infested tree cut down in time, it will not be burned promptly, 

 but left where the beetles can readily emerge, so that practically nothing 

 is accomplished in checking the pest. 



A determined effort is now being made to save the remaining white 

 birches on the University Campus. This autumn all the infested trees 

 showing dying tops are being removed and promptly burned. In cities 

 and towns where this insect is killing the white birches, there should be 

 enacted an ordinance compelling the authorities to promptly cut and burn 

 in autumn, winter, and surely before May ist, the infested trees in the 

 parks, and if possible requiring owners of private grounds to do the same. 

 The mere enactment of such an ordinance will not often accomplish the 

 desired result. Public opinion must be behind such a measure to enforce 

 it. Ithaca, Buffalo, Rochester and other New York State cities are now 

 face to face with the problem of checking this pest or of losing their white 



