8 FARMERS’ BULLETIN 108. 
METHODS OF CONTROL. 
The protected and concealed manner of life of this borer, as shown 
by the life history, which will apply in the main to borers in general, 
renders it very difficult of treatment by means of insecticides or other 
direct measures. The most efficacious remedial measure consists in 
cutting off and destroying affected branches and in the injection of 
bisulphid of carbon into the holes or burrows where the larve are 
at work. 
PRUNING AND CUTTING BACK. 
Twigs or branches which, by their wilting or by the presence of 
burrows showing accumulations of frass or sawdust-like castings at 
their entrances, indicate the presence of this borer should be care- 
fully searched out, the smaller ones pruned away and the larger ones 
eut back, and the amputated portions promptly burned. The stubs 
should be coated, preferably with grafting wax, to prevent the en- 
trance of other insects or the spores of decay-producing fungi, 
although coal-tar preparations containing mineral substances are in 
somewhat general use for this purpose. After windstorms the 
affected branches which have fallen to the ground and those which 
remain attached to the tree should be collected and burned. Wher- 
ever trees show that they are past recovery it is best to take them 
out and promptly destroy them. The word “promptly” is used 
advisedly, since this insect, as previously stated, frequently migrates 
from one twig or branch to another. 
INJECTING BISULPHID OF CARBON. 
In the case of young and rare trees and others which show only a 
few larval burrows in the bark, bisulphid of carbon is the best remedy 
and one which has been in general use against the present species in 
the public parks of New York City. It is injected into the openings 
of the burrows, and the openings are immediately afterwards closect 
with various substances. For this injection a mechanic’s long- 
spouted oil can of small size may be used on large trees, but against 
a related species the writers have made very good use of a small glass 
syringe, such as may be purchased at drug stores for about 10 cents. 
These glass syringes are most serviceable, because the exact amount 
of bisulphid may be seen when drawn into the syringe and because 
there is no threading to be injured by the reagent. Metal syringes 
may also be used, but it is more difficult to measure the exact amount, 
and the bisulphid acts on the leather packing. Rubber syringes are 
not serviceable because of rapid corrosion. About a teaspoonful of 
the liquid bisulphid is sufficient for each burrow. 
