16 FARMERS’ BULLETIN 675. 
be removed. This would include service (figs. 18, 19), mountain ash, 
wild crab, and thorn trees in woods, as well as the cultivated fruit 
trees. 
PAINTS AND WASHES. 
Paints and washes of various kinds have frequently been recom- 
mended for use on the trunks of trees, both to prevent the beetles 
from depositing eggs and to kill the borers within the trees. Experi- 
ence has shown that it is easier by such means to prevent the eggs 
from being laid than to kill the 
borers. Some orchardists report 
success by applying pure kerosene 
to the bark of affected trees at the 
places where castings show borers 
to be at work. The kerosene is sup- 
posed to penetrate the burrow to 
the insect and kill it. Others have 
found that this treatment does not 
destroy enough of the borers to 
make the remedy worth while, and 
that in addition the kerosene may 
kill the bark at the point cf applhi- 
eation. The danger of injury to 
trees by the use of kerosene or other 
mineral oil practically prohibits 
the use of these substances. Milder 
solutions, apphed in the same way, 
while not so likely to injure the 
trees, are even less fatal to the 
borers. 
On the other hand, a heavy ap- 
plication, made just before the be- 
ginning of the egg-laying season, of 
some thick paint that will not injure 
the trees and that will maintain an 
unbroken coat on the bark for two 
Frc. 17.—Tools for use in removing or three months is very effective in 
Rikaspestipiad Pits oe preventing the female from placing 
her eggs in the bark. The beetle in 
slitting the bark with her jaws, preparatory to inserting the egg, will 
55) 
very rarely, if ever, make an opening through such a thick coat of 
paint. 
3efore applying paint for this purpose the earth around the base 
of the tree should be removed with a garden trowel or hoe to a depth 
of 3 or 4 inches. Bark scales and adhering earth should then be 
scraped from the space to be covered, and the paint applied with a 
