18 FARMERS’ BULLETIN 675. 
‘measure of protection to the tree, providing a heavy coat is applied 
in a thorough manner just previous to the beginning of the egg-laying 
season of the borers. The natural growth of the tree will in time 
cause the paint to crack, 
but the coat formed by 
one painting will remain 
intact and protect the 
tree during one egg-lay- 
ing season if applied at 
the proper time. Better 
results are likely to be 
obtained from this treat- 
ment on young, smooth- 
barked trees than on old 
trees on which the rough 
bark makes a thorough 
job of painting more dif- 
of the Bureau of Ento- 
mology, apple trees are 
not injured by the white- 
lead paint when used as 
directed. Others have 
reported injury from 
supposedly pure white- 
lead paints, but it is pos- 
sible that these contained 
foreign and _ injurious 
substances. Those plan- 
ning to use the raw lin- 
seed oil and white-lead 
paint should insist on 
receiving this article. 
There are several so- 
called tree paints and 
pruning paints on the 
market that are valuable 
for this purpose and ap- 
Fic. 19.—Roundheaded apple-tree borers working in pear to be safe for the 
young service tree. (Original.) trees. Annual applica- 
tions of any of these paints will be necessary. 
Gas tar has been used with some success against peach-tree borers, 
but should be used with caution on apple trees, as there is serious 
danger of injury to the bark and wood, Axle grease and paints con- 
ficult. In the experience - 
