4) 
of the trees. There is no doubt, from Mr. Slingerland’s work, that 
gas tar, lightly and properly applied to the trunk of the tree, will 
not endanger the health of the plant, at least under the conditions of 
temperature and moisture obtaining at Ithaca, N. Y. Its careless 
application, however, will probably result disastrously and it may 
be less safe in regions with moist and hot summers. In using this 
substance, therefore, one should first experiment with a few trees to 
be sure that a method is not adopted that will do material damage 
to the orchard. The ordinary gas tar is employed, heating it slightly 
so that it may be painted readily on the bark. Mr. Slingerland’s 
experience showed that it freed the trees from four-fifths to all of 
the borers, but a small percentage of the trees becoming infested. 
All of these applications should be made early in June, or before the 
moths are out. 
Tn addition to the above, a very large number of substances have 
been experimented with, including all which seemed to offer any likeli- 
hood of preventive value. Of these, those named above have yielded 
the best results. 
REMEDIAL MEASURES. 
The methods just outlined are preventive, and are designed to keep 
the peach-tree borer from ovipositing or to destroy the young larva 
before they have entered the bark. After a tree is once infested these 
external applications are of no avail, except to prevent additional 
attack. To kill the larve in the trees two or three methods may be 
followed. The old-time process of digging or cutting the larve out 
with a knife is undoubtedly the most effective and useful of all means 
of controlling the peach-tree borer, and is followed by some orchard- 
ists altogether, no effort being made to protect the trees from attack, 
reliance being placed solely in the removal of the larve in autumn or 
summer. 
In California the related peach-tree borer referred to in the opening 
paragraph has been effectively controlled by the use of bisulphid of 
carbon. This substance has given very satisfactory results as reported 
by Prof. C. W. Woodworth; but, on the other hand, in the case of 
experiments made with it in New York by Mr. Slingerland, it proved 
a complete failure, and was condemned by him on account of its cost 
and its being dangerous to the health of the tree, and, at the same time 
ineffective as a means of destroying the borer. Its efficiency depends 
a great deal on the character and condition of the soil, and, taking the 
difficulty of determining and controlling this into account, and also 
the other objections to it, namely, cost and danger to the trees, it seems 
not a method to be generally recommended. 
Douching the bases of the trees copiously with boiling hot water 
will also destroy the larvie, but this entails the transporting of quan- 
(Cir. 54] 
