SCALE-INSECTS. 31 
cineus (Alderton) ; in Nelson it is said to be used 
beneficially against Jcerya purchasi. It does not, 
however, kill the eggs with certainty (Personal experi- 
ment). Applied warm, and properly diluted, it may 
be recommended as a good remedy; but applications 
of it shouid b> repeated. 
9. Kerosene. Seemingly the most valuable of all remedies, 
when properly applied. ‘* Almost the only substance 
which will certainly kill the eggs without at the same 
time destroying the plant”? (Hubbard). 
But the application of this remedy must be care- 
fully performed. Some trees may endure it without 
injury, even undiluted or unmixed; but this is 
scarcely to be expected, and the oil should therefore 
be applied in some mixed form. Also, it is important 
to remember that a hot sun increases the injurious 
effect of kerosene ; consequently winter, or cloudy wea- 
ther, should be chosen for its employment. 
(a.) Pure kerosene. As just stated, it is probably 
not advisable to use this. Still, “a young shoot of 
orange, not more than fourteen days old, was un- 
injured by an application of pure kerosene which 
thoroughly wet every leaf;’’? (Comstock); and Le- 
canium hesperidum on ivy, similarly treated, was de- 
stroyed, without injury to the plant (ibid.). 
(6.) Kerosene and milk. An excellent mixture, if 
milk can be obtained cheap (Riley; Hubbard; 
Comstock). It must be applied in the form of an 
“emulsion,” sprayed over the tree or brushed on the 
bark. Hubbard gives the following directions for 
use: Heat the milk nearly to boiling-pomt and mix 
with double the quantity of kerosene ; churn violently 
from ten minutes to half an hour, according to tem- 
perature, until a creamy thick fluid is obtained ; 
dilute this with nine or ten times the quantity of 
water. The mixture is of course purely a mechanical 
one, as far at least as the water is concerned, and it 
must be kept constantly stirred, to prevent the sub- 
stances from separating from the water. For ever- 
green trees impel the mixture on leaves and branches 
in the finest possible spray. Sour milk is as useful as 
fresh, 
