MONTANA EXPERIMENT STATION. 227 



known to all as sun-scald, and makes typical conditions for the bor- 

 ers. Dead or worthless trees should not be allowed to stand and 

 become a menace to the healthy ones. It is a bad practice to have 

 a brush ])ik' made up of dead trees and prunings at the side of the 

 field. Such piles should be burnt very frecpiently, for they soon 

 become nurseries of pests. 



In a locality known to be infested with this borer it is often de- 

 sirable to use deterrent applications on the trunks and larger limbs 

 of both weakened and healthy trees. For this purpose, a number of 

 substances have been recommended. Some use old newspapers as 

 mechanical barriers placed about the base of the tree. 



Mr. Chittenden recommends that these papers be put on the 

 trunk for about two feet from the ground up, and that above the pa- 

 per a carbolated or akaline wash be applied. Wire netting is some- 

 times used. 



The paper and netting not only prevent the deposition of eggs 

 but also prevent the escape of the beetles that emerge underneath 

 them. 



Among the substances that may be used as washes to make the 

 surface of the trees objectionable to the adult beetles and so prevent 

 them from depositing their eggs are the following: 



1. A thick solution of whale-oil soap. 



2. Soft soap rendered thick by the addition of caustic soda or 

 potash in solution. 



3. Either of the above w^ashes would probably be made more 

 effective by the addition of crude carbolic acid at the rate of one 

 pint to ten gallons of the wash. 



James Good, 939 and 941 North Front Sstreet, Philadelphia, Pa., 

 offers for sale a product known as Caustic Potash Whale-oil Soap, 

 which of itself would be a good substance for this purpose. It 

 should be diluted with sufficient water to make a thick fluent mass, 

 and applied to the trunk and limbs of the trees to be protected. 

 Such washes when not of a quality that makes them injurious to the 

 hands, are sometimes applied by a man wearing old mittens or socks 

 that are saturated with the wash. 



