Aphids Injurious to Orchard Fruits, Etc. 93 
SEASONAL HISTORY. 
As in the case of the black cherry aphis, the eggs of this insect are 
laid on the cherry twigs. After the stem-mothers have become ma- 
ture and produced young, these latter crowd the terminal leaves. 
Winged forms (fig. 14) are produced during early summer, and by mid- 
summer the insects usually have disappeared from the trees. The 
winged forms migrate to grains and grasses and here produce colonies 
which are very similar to those of the apple-grain aphis. Here 
they live throughout the summer, and in the fall winged forms 
return to the cherry trees to deposit the egg-laying females. 
THE CHOKECHERRY-GRAIN APHIS.' 
The chokecherry-grain aphis is very similar indeed to the oat 
aphis of Europe and it is not improba- 
ble that it is the same species. The 
wingless forms (fig. 15) are a dark 
olive green, irregularly mottled with a 
darker color and dusted with a whitish 
powder, especially along the sides of 
the abdomen and in the abdominal 
wrinkles. The winged forms have the 
head and thorax shiny black, and the 
general body color dark olive with 
black markings on the abdomen and 
black honey tubes. The pupa, which 
later becomes the winged form, has 
powdery tufts along the sides and across = Me aes Breet 
the hind part of the abdomen. The pie es ae Bega ius 
insect attacks the terminal twigs of 
the chokecherry and causes a twisting and curling of the leaves. 
(Fig. 16.) 
SEASONAL HISTORY. 
The complete life history has not been worked out. Undoubtedly 
the eggs are laid upon the cherry and hatch to stem-mothers, which 
with their young cause the curling of the leaves. Winged forms ap- 
pear in June and continue to be produced for some weeks. These 
migrate to grains and produce colonies there somewhat similar to 
those of the apple-grain aphis. On the grains, however, the insects 
do not possess the mealy covering seen on the cherry forms. In the 
fall migrants return from the grains and grasses to the cherry and 
here produce the oviparous females which lay the overwintering eggs. 
THE RED AND BLACK CHERRY APHIS.’ 
The red and black cherry aphis lives in dense red masses on the 
young shoots of the black cherry. It does not attack the leaves, but 
1 Rhopalosiphum pseudoavenae (Patch). 2 Aphis tuberculata Patch. 
