MEANS AGAINST CICADA IN UNDERGROUND LIFE. 145 
lizers, which will give the plant a more vigorous growth, will hasten 
the healing process. With young trees the worst affected branches 
should be removed, and the less injured ones protected from other 
insects while they are healing by coating the wounded parts with 
grafting wax or a moderately hard soap. These protective coverings 
should be renewed at least once a year, preferably in the spring, until 
the wounds are entirely healed over. In the case of a badly injured 
tree that has been recently budded or grafted, it may be well to cut 
it back nearly to the bud or graft, so that an entirely new top may 
be made. 
MEANS AGAINST THE CICADA IN ITS UNDERGROUND LIFE. 
While it is probably true, as we have already stated, that the Cicada 
in its underground life does not work any serious injury to plants on 
account of the very insignificant amount of nutriment which it annu- 
ally draws from the rootlets, nevertheless in exceptional cases, where 
the ground is suspected of being very thickly populated with the larve 
and pupe of this insect, it imay be deemed desirable to undertake their 
extermination. This may be accomplished, as suggested, by using the 
remedies ordinarily employed against other subterranean insects, such 
as the Phylloxera and the apple root-aphis, with this difference, that 
the poisons will have to be introduced more deeply into the soil 
unless applied in the first or second year after the larve have begun 
their development. 
If taken in time, the number of the larve in the soil may be greatly 
reduced by cutting off the branches of the trees which have been 
thickly oviposited in, thus preventing the hatching of the eggs. It 
will rarely, however, be possible to so completely eliminate the eggs 
from the tree as to prevent the entrance of the larve into the soil in 
considerable numbers. 
Of the means employed against subterranean insects two are espe- 
cially suitable for the destruction of the larve and pupe of the 
Cicada—namely, bisulphid of carbon injected into the ground and 
tobacco dust incorporated in the soil. 
Tobacco dust has a manurial value and is not at all injurious to 
plants. Its value against Cicada larve is purely theoretical, but there 
is little doubt but that if it can be incorporated in the soil some dis- 
tance below the surface—namely, by first removing 6 inches or more of 
the top soil—it will effect the destruction of many of the delicate larvee 
and pup of the cicadas. This dust is a waste product of tobacco 
factories and costs about 1 cent per pound, and is worth nearly its cost 
as a fertilizer. 
Bisulphid of carbon, the popular French remedy for the grape root- 
aphis, will undoubtedly prove an efficient means against the Cicada in 
31117—No. 71—07——10 
