APHIDS 49 
Fig. 5. Aphids on Apple Blossom. At O is seen a stem-mother of the 
Rosy Apple Aphis.—Del. Ex. Sta. 
green. The sexes mate and the female 
deposits about three winter eggs on the 
twigs or in crevices in the bark of the 
trunk and large limbs. The injury caused 
by this aphid is similar to that caused 
by the Green Apple Aphis. It can be 
controlled in a like manner. 
The European Grain Aphis 
Aphis padi L. 
Although quite injurious in the east- 
ern United States this species is rarely 
an apple pest in the West. In color and 
size it very much resembles the Green 
Apple Aphis, but may always be distin- 
guished from that species by the very 
small apical cell of the wing. The life 
history is very similar to that of the 
Rosy Apple Aphis, the winter eggs be- 
ing laid on fruit trees and the summer 
generations living on grasses. In the 
South and in California the lice winter 
also on grasses. When infesting the 
apple it may be controlled in the man- 
ner suggested for the Green Apple Aphis. 
The Clover Aphis 
Aphis bakeri Cowen 
This plant louse infests apple trees in 
certain portions of the United States, 
notably Colorado. Its life history is very 
similar to that of the Rosy Apple Aphis, 
the summer generations living on clover 
and alfalfa. The stem-mother on the 
apple in spring is dark red or reddish- 
green while the migrants are pale green 
with orange spots at the base of the cor- 
nicles. The remedies for the Green Apple 
Aphis will control this aphis on the apple. 
The Woolly Apple Aphis 
Schizoneura lanigera Hausm. 
This is the most injurious aphid in- 
fecting pomaceous fruits and is found all 
over the world wherever apples and pears 
are grown. It has been known in Hurope 
for over 100 years. It is not known in 
what part of the world this insect origi- 
nated but recent investigations seem to 
show that it is identical with the Ameri- 
can Elm-gall Aphis * (Schizoneura ameri- 
cana Riley), a native American aphid. 
The louse attacks the trees below, as 
well as above, the surface of the ground 
and is thus very hard to: eradicate. The 
somewhat complex life history is as fol- 
lows: The young hatch in early spring 
from winter eggs placed in crevices in 
*Edith M. Patch, Maine Bull. 203. 
