8 
acts with wonderful energy, scalding when used at the rate of 1 pound 
to 100 gallons from 10 to 90 per cent of the foliage; the action of the 
other arsenites remains practically the same, with perhaps a slight in- 
crease in the case of London purple. 
With the peach these poisons, when applied alone, even at the rate 
of 1 pound to 300 or more gallons of water, are injurious in their action, 
causing the loss of much of the foliage. 
By the addition of a little lime to the mixture, London purple and 
Paris green may be safely applied, at the rate of 1 pound to 125 to 150 
gallons of water, to the peach or the tenderest foliage, or in much 
greater strength to strong foliage, such as that of the apple or most 
shade trees. 
Whenever, therefore, the application is made to tender foliage or 
when the treating with a strong mixture is desirable, lime water, milky, 
but not heavy enough to close the nozzle, should be added at the rate 
of about 2 gallons to 100 gallons of the poison. 
With the apple, in spraying for the codling-moth, at least two appli- 
cations should be made, the first after the falling of the blossoms or 
when the apples are about the size of peas, and the second a week or 
ten days later. The first brood of the codling moth lays its eggs in the 
flower end of the young apple, and the worms upon hatching gnaw their 
way into the interior of the apple, and on sprayed trees get poisoned 
in so doing, an infinitesimal amount being sufficient to destroy so min- 
ute a worm. The second spraying is for the purpose of destroying 
larvee hatching from eggs which may be laid after the first spraying, as 
the arsenic is gradually washed off by rains. 
For the plum curculio on the plum, cherry, peach, etc., two or three 
applications should be made during the latter part of May and the first 
half of June. The poison in this case is applied for the purpose of de- 
stroying the adult curculios which hibernate and gnaw into the young 
growth of the trees and even into the hard young fruit before laying 
their eggs. The eggs are pushed under the skin so that the larve are 
not ordinarily affected by the poisoning. 
In the case of most leaf-feeding insects one shape spray on the first 
indication of their presence. 
Caution necessary in the use of these insecticides.—The relative sus- 
- ceptibility of apple, plum, and peach has just been indicated under the 
head of arsenical poisons, and these remarks apply equally well to the 
use of the kerosene emulsions. In the case of other plants thorough 
experiments are still necessary, and all insecticides should be used in 
comparatively high dilution. Tender-leaved plants, such as melons and 
cucumbers, are more readily injured; while plants with firmer and smooth 
leaves, like the orange, are least affected. Annual plants, such as cab- 
bages and other garden vegetables, are more susceptible than perennials; 
but in the case of root crops, such as beets, turnips, radishes, and potatoes, 
there is not the same need of caution as to damage to foliage. Damage 
