The More Important Apple Insects. 25 
The insect passes the winter in the egg stage, the eggs being laid on twigs 
and water sprouts. They are yellowish green when freshly laid, later changing 
to a glossy black. The so-called stem-mothers hatch from these eggs about 
‘the time the buds begin to burst. Frem 9 to 
17 generations are produced during the season, 
following which the sexual individuals appear 
and deposit the overwintering eggs. The wing- 
less viviparous female is of a uniform green 
color, darkening with age, frequently having a 
yellowish head. The winged viviparous female 
is of a pea-green color, with head and thorax 
shiny black, wings transparent. and appendages 
more or less completely black. 
Thorough spraying of trees as the buds are 
bursting in the spring (delayed dormant treat- 
ment) as described for the rosy aphis (pp. 23-24) 
will be of much value in controlling this species. 
By midsummer, however, the 
aphids may beeore abundant FG) dd “<Gredirapote wphis ‘on 
again and in the case of apple foliage. 
young orchards do consider- 
able damage in checking tree growth. It is a question of 
judgment on the part of the orchardist whether or not to 
spray, in view of the only partial effectiveness of treat- 
ments due to the curled and rolled-up leaves. If the in- 
jury is pronounced, spraying with the 40 per cent nicotine 
sulphate and soapy water spray is probably advisable, 
care being taken to apply the liquid thoroughly and with 
force. 
APPLE-GRAIN APHIS.” 
Fruit growers are often unnecessarily alarmed early in 
the spring upon finding the swollen apple buds covered 
uals of apple- With small, light-greenish aphids 
grain aphis clus- (fig. 45) awaiting an opportunity to 
tered on swollen feed upon the first succulent leaf 
“eth bud. En- tissue that appears. Later when the 
tree is in bloom, the same aphids 
may appear in hordes in the blossoms, often 15 or 20 in- 
dividuals to a single flower. This is usually the apple- 
erain aphis, which, even when abundant, is believed to 
cause no important injury, since it leaves the apple shortly 
after the blooming period, migrating to grains and grasses, 
on which it passes the summer. 
The apple-grain aphis, or “apple bud aphis,” as it is 
sometimes called, is quite widely distributed throughout 
the United States. It passes the winter in the egg stage. . ae 33 
The eggs (fig. 46), which are laid in crevices of the bark rene eae ee 
or on the twigs, are pale green when first deposited, later larged. 
changing to a glossy black. Some of the eggs hatch pre- 
maturely during warm days in- winter and are destroyed, but the majority 
do not hatch until-the buds commence to swell. Several generations are pro- 
duced by the time the apple blooms have fallen, at which time the aphids migrate 
Fig. 45. — Individ- 
Fic. 46.—Eggs of 
4 Rhopalosiphum prunifoliae Fitch. 
