REMEDIES AGAINST FOREST INSECTS. 35 
aud the conditions of application also vary greatly. Unleached wood 
ashes should not be applied too freely in contact with the body of the 
tree or the roots, since water leaching through them may contain pot- 
ash enough to iujure the plant. Lime in any reasonable quantity could 
hardly cause injury. The application of either of these is generally 
beneficial and tends to destroy and repel insects from the base and roots 
of trees. The ashes act beuficially as a fertilizer. 
Coal Ashes and coal Bust. — Coal ashes and coal dust have been used 
for this purpose, but their effects could only be mechanical, and, while 
doubtless of value to the plant as a mulching, could have but little 
effect on insects. The beneficial effects of either of these used dusted 
on the plant are doubtful, except in cases of soft-bodied slugs (saw-fly 
larvae), where their action is generally good. 
Pyrethrum, Hellebore, Sulphur. — These well known insecticides may 
be used in powdered form or may be mixed with water and applied in 
a spray. While they can not be recommended for general forest work, 
cases will frequently arise warranting their use in a limited way against 
aphids and other soft-bodied insects. Hellebore is of especial value 
against saw-fly larvae. Sulphur is a valuable agent against the red 
spider (Tetranychus telarius) and may be used alone or in connection 
with emulsion of kerosene. 
Alkaline lYashes : potash Lye and soda Lye. — Alkaline washes are 
solutions of crude soda or potash, or soap preparations of these sub- 
stances. Concentrated soda or potash lye can be purchased at the 
stores, and are often used as washes for aphids and coccids with con- 
siderable success. Of these the potash lye is to be preferred, as its 
action on the tree is not so harmful as the soda lye. The best possible 
source of a caustic wash is the potash lye leached from wood ashes* 
Crude lye washes should be used with caution, since when too strong 
it injures both branches and foliage. Definite statements as to the 
strength to be used can not be made. The different brands of concen- 
trated lye vary much in composition, so that it will always be advisable 
to make test applications before general work is attempted. In the 
preparation of washes, one can (1 pound) of lye is dissolved in from 3 
to 5 gallons of water; the stronger solution is very injurious to tender 
plants, and even the weaker one is entirely too harsh for a safe wash ; 
yet, if diluted much more, its effect on the iusect will be impaired. 
The same quantity of lye used in the preparation of a soap will give 
better results, and its use will not then be attended with like danger 
to the plant. 
Alkali?ie Washes : Soaps. — Soap preparations are made from either of 
the above lyes with grease or oils of any kind and in my experience are 
much preferable to the crude lyes. 
Auy soft or jelly soap makes a good wash for Aphides, and for this 
purpose need not be strong ; for Coccids the strength should be greater. 
The preparation known as " whale-oil " soap has a more or less stand- 
