Z 
E Aphids Injurious to Orchard Fruits, Etc. 9 
infested, often so much so as decidedly to check the growth. Such 
trees are likely to be more or less sooty in appearance and overrun 
with ants. Water sprouts and the shoots of top-worked trees are 
especially liable to attack. This is the species commonly present on 
the shoots of apple nursery stock, and much complained of during some 
years. Theworkofthisaphidis at times confused with that of the apple 
leafhopper,! which distorts the leaves in a manner more or less similar. 
The green apple aphis is uniformly green, with black legs, feelers, 
and honey tubes. (PI. II, E,G,I.) Occasionally forms are met which 
are yellowish, instead of a 
distinct green. The winged 
forms (Pl. II, H) have a 
black head and body and a 
uniformly green abdomen. 
The males and egg-laying 
females, which are met dur- 
ing the fall, are somewhat 
smaller and different in col- 
or from the agamic forms 
(Pl. II, L, M) which oc- 
cur throughout the sum- 
mer. The males are orange 
yellow, sometimes with a 
brownish tinge, and the fe- 
males dark green. 
SEASONAL HISTORY. 
The eggs when first laid 
are yellowish green, later 
turning to polished black. 
They are laid in the fall 
upon the smooth twigs and 
water sprouts of the apple 
fee tte PTS Vil < fie: 5), 
and seem to be laid rarety 
on the trunks and larger L 
limbs. A very small per- Fig. 4—The green apple aphis: Curled condition of apple 
: foliage due to this insect. 
centage of the eggs of this 
species, sometimes as low as 2 per cent, hatches. Hatching occurs 
at about the same date in the spring as in the case of the rosy aphis. 
The young stem-mothers mature in about 10 days, and in about 
24 hours after becoming adult begin to produce living young, repro- 
duction continuing for about two weeks. Between 40 and 50 living 
young are produced by each stem-mother, at the average rate of 
4 a day, although many more may be born daily. Of these young 
1 Empoasca mali Le Baron. 
166596 °—20—Bull. 1128 
9 
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