Aphids Injurious to Orchard Fruits, Etc. 47 
This is especially true of varieties subject to “fruit spots’? or 
“stigmonose,”’ since these troubles have been shown by the Bureaus 
of Plant Industry and Entomology to be due, in part at least, to the 
activities of aphids. 
CONTROL OF APHIDS ON PLUM, PEACH, CHERRY, ETC. 
The several aphids which occur on plum, as well as the green 
peach aphis, pass the winter on the trees in the egg stage, hatching 
in the spring about the time when foliage appears. None of these 
species curls the foliage to the same extent as do some of the apple 
Fig. 34.—Young apple shoot too far expanded for successful aphid spraying. Enlarged. 
aphids, and thorough spraying of the trees when the insects are in 
evidence usually will be satisfactory. Nevertheless spring spraying 
against the stem-mothers is desirable in orchards where the insects 
have been troublesome regularly or where winter eggs are seen to be 
present in numbers. 
The black peach aphis, which winters on the roots of the peach, 
should be treated as soon as the insects are observed to be present 
on the foliage and twigs, and in regions where they are likely to be 
troublesome, as on nursery stock in sandy situations, careful watch 
should be made for their first appearance. 
The black cherry aphis is likely to be in evidence each year on 
cherries. The insect winters on the trees in the egg stage and the 
eggs hatch somewhat in advance of the opening of the buds. Since 
thisspecies causes a decided curling of foliage so that later treatments 
