The More Important Apple Insects. 5 
midrib. This leaf-feeding habit is of negligible importance as to foliage injury, 
but it is of some consequence from the control standpoint in that some larvee may 
be killed or weakened by eating the poison before they reach the fruit. 
The codling moth passes the winter in the larva stage, inclosed in a silken 
cocoon (fig. 4), which is about three-fourths of an inch in length. The over- 
wintering larya is about the same length as the cocoon and is usually of a dirty 
white color with a brown head. The larvee normally make their cocoons beneath 
the bark scales of the trunk and larger limbs, in tree crotches, and in decayed 
stubs resulting from improperly pruned limbs; they also spin up in trash about 
the orchards, in cracks of the soil adjacent to the tree, in field harvest boxes, 
in packing houses, etc. In the spring the larva transforms successively into the 
pupa (fig. 4) and moth stage (fig. 5). The pupa is about half an inch in length 
and varies in color from dark yellow to brown. The abdominal segments are 
movable and each is provided with a double row of spines, except the terminal 
segments, which have but one each. The moth is somewhat variable in size, but 
the wing expanse averages about three-fourths of 
an inch. The front wings are crossed by irregular 
dark and light bands except the tips, each of 
which bears a dark metallic brown spot or ocellus. 
The moth, which is seldom seen by the orchardist, 
usually conceals itself in or about the tree during 
the day. but becomes more active about twilight, 
when it deposits a majority of its eggs. These are 
laid on both the leaves and fruit, the first-brood 
eggs being usually found on the foliage, while 
those of the summer brood are as a rule deposited 
on both the fruit and foliage. The egg is about 
the size of a pinhead, flat, round to oval in shape, 
the surface being covered with a network of ridges, 
and when freshly laid is pearly white in color. 
The young larva which hatches from the egg feeds 
chiefly upon the fruit, and after attaining its full 
growth leaves the apple and spins its cocoon on 
the tree trunk or in other places, as elsewhere 
noted. In districts having two or more genera- IIc. 
tions, part of the first-brood lary soon transform 
to pupz, while the others remain in the larva 
stage until the following spring. Those that transform the sume season as 
hatched produce a new generation. In the more northern fruit-growing dis- 
tricts of the United States, as in New England, there is a small second genera- 
tion, whereas in some of our extreme southern regions, as in the Pecos Valley 
of New Mexico, as many as three generations and a partial fourth may develop. 
In any locality the relative abundance of worms, especially those developing 
late in the season, varies from year to year, largely in accordance with the 
weather conditions. If the season is early, dry, and hot, a larger number of 
worms than usual will be produced, whereas during late. cool, and wet seasons 
the reverse is true. The orchardist should therefore study the seasonal weather 
conditions, and if these are fevorable to the codling moth supplemental spray 
treatments should be applied. 
The length of the different stages of the codling moth varies with the 
climatic conditions. In the spring the pupa stage averages about 3 weeks, 
with an approximate range from 2 to 6, while later in the season *his stage 
2 
r. 
Apple infested with 
the codling moth. Note frass 
pushed out of larval burrow. 
