6 
that sparrows sometimes destroy the eggs or young larvee in such 
places. Smith has expressed the belief that when the insect suc- 
ceeds in getting away from the outskirts of cities its enemies increase 
in number, many insectivorous birds aiding in holding it down. 
During the day the moths must be fed upon by birds and later 
by bats and night-flying birds. The habit of the larve of desert- 
ing one twig and migrating to a larger one undoubtedly leaves them 
exposed to the same natural enemies, as this has been observed to 
happen in the daytime as well as after nightfall. It follows that the 
protection of native birds, especially the woodpeckers and related 
species, will greatly assist in restraining the undue increase of this 
borer. 
METHODS OF CONTROL. 
The protected and concealed manner of life of this species, as 
shown by the life history, which will apply in the main to other 
borers also, renders it very difficult of treatment by means of insect- 
icides or other direct measures. The most efficacious remedial meas- 
ure consists in cutting off and destroying affected branches and 
in the injection of bisulphid of carbon into the holes or burrows 
where the larvee are at work. 
Pruning and cutting back.—Twigs or branches which, by their 
wilting or by the frass which accumulates at the entrance to their 
burrows, indicate the presence of this borer, should be carefully 
searched out, the smaller ones pruned away and the larger ones 
cut back, the amputated portions being promptly burned. After 
windstorms, the affected branches which have fallen to the ground 
and those which remain attached to the tree should be collected and 
burned. Wherever trees show that they are past recovery it is best 
to take them out and promptly destroy them. The word promptly 
is used advisedly, for this insect, as has been shown previously, fre- 
quently migrates from one twig or branch to another. 
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 YorkCity. It 
is injected into the openings of the burrows, and the openings are 
afterwards closed 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 any drug 
store for ten cents. These glass syringes are most serviceable, be- 
cause the exact amount of bisulphid may be seen when drawn into 
the syringe and because the reagent does not injure the thread pack- 
(Cir. 109} 
