29 
wholly free from this pest. Nor is this an isolated case, since I saw 
the same thing in another pear orchard located several miles from this 
one. Mr. Richardson informs me, however, that the fruit of this tree 
is almost worthless. 
Wishing to test the effects of the above wash on growing trees, I 
sprayed a prune, peach, apricot, apple, and orange tree on the 12th day 
of May, between the hours of 10 and 11 a. m., sun shining, light breeze. 
I examined these on the 11th of June; on the prune all of the fruit had 
dropped off, and upon one-third of the leaves were dead brown spots, 
these spots not exceeding one-sixth of the entire surface of any of the 
leaves; on the peach all of the fruit was dead, but still clinging to the 
tree, and half the leaves had brown spots in them, these leaves being 
much more injured than were those on the prune tree; on the apricot 
the fruit was not injured in the least and three-fourths of the leaves 
were uninjured, but the remaining leaves had small brown spots in 
them, these spots not exceeding one-fifteenth of the surface on any of 
the leaves; on the apple all of the fruit had dropped off and half the 
leaves had large brown spots in them, these spots sometimes exceeding 
one-half of the entire surface of the leaf; on the orange nearly all of 
the fruit had dropped off (the young oranges being about half an inch 
in diameter), but the leaves were uninjured. 
This indicates that of the different kinds of fruit thus experimented 
upon the apricot was the hardiest and was the least affected by the 
wash ; next to the apricot is the orange, then the prune, after this the 
peach, the apple having suffered most from the effect of the wash. 
The orange tree experimented upon was infested with the Yellow 
scale (Aspidiotus citrinus), and also with the Black scale (Lecanium olew 
Bernard), and all of these, as well as the eggs of the Black scale, were 
destroyed by the wash. 
According to the scale of prices furnished me by the Los Angeles 
Soap Company of this city, the material for making 100 gallons of the 
above wash, when purchased in large quantities, would amount to $1.14, 
being but a trifle over 1 cent a gallon for the diluted wash. 
The materials used in preparing the above wash are the same as 
those I used in spraying orange trees last season for the destruction of 
the Ked scale (Aspidiotus aurantit Maskell), an account of which is 
given in my report to Professor Riley for last year, published in Bulle- 
tin No. 22 of the Division of Entomology (pp. 10-14); but the spray I 
then used was only three-fifths as strong as the one I used for the de- 
struction of the San José scale as above described. On the 19th of 
December I tested the spray of the same strength that I had used 
for the Red scale on orange trees, but it did not prove fatal to all of 
the San José scales that it came in contact with. 
The question as to the manner 1n which the above resin spray proves 
fatal to the scale insects—whether the caustic property imparted by the 
caustic soda is the destructive agent, or whether it is the suffocating 
