SCALE-INSECTS. 33 
stance better for destroying Coccids and their eggs 
than kerosene in the form of milk or soap emulsion, 
diluted with water for evergreens or for trees with 
insects on the leaves as well as on the bark. Pro- 
bably, for deciduous fruit-trees the kerosene-and-oil 
mixture is the best. 
The great point in favour of this substance is that 
at destroys the eggs; this, few if any of the others. 
will accomplish. 
10. Lime. Of no avail whatever. 
11. Lye. Concentrated lye is very frequently recommended. 
In the New Zealand Parliamentary Papers (Codlin 
Moth Committee Report, 1885, page 7) several state- 
ments will be found apparently most favourable to it; 
yet im places we find admissions that “it cannot reach 
all the eggs.” In America generally, it has not been 
found satisfactory : “inferior to kerosene in killing- 
power, and far more injurious to trees when used in 
solutions strong enough to be effective as insecticides.” 
It is quite possible that the action of lye on the 
fungus accompanying the scale-imsects (see Chap. ITI.) 
may have led “ practical” gardeners to imagine that 
it cleaned their trees of scale. Comstock says, “I 
saw most excellent results from the following mix- 
ture: Ilb. concentrated lye, one pint gasoline or 
benzine, half pint oil, five gallons water.”? Probably 
the good results here were due, not to the lye, but 
to the gasoline and oil. 
12. Pyrethrum. Useless against Coccids (Comstock). 
13. Salt. Useless (Comstock). 
14, Soap. Undoubtedly a valuable remedy, and perhaps, in 
some cases, as efficient as kerosene; but it does not 
destroy the eggs. A solution of {lb. of soap to a 
gallon of water, applied hot, was entirely successful 
in California: three months after its application no 
living scale-insect could be found (Comstock). The 
time of the year is not stated. In another case the 
solution was applied cold: ‘four days after no living 
insect could be found ;” but, again, the time of the 
year is not stated, and no mention is made of the 
eggs. Still, a strong solution of soap may be said 
