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THE MORE IMPORTANT APPLE INSECTS. 
By A. L. QuAINTANCE, Entomologist in Charge, and BK. H. Steaier, Mintomologist, 
Fruit Insect Investigations, Bureau of Entomology. 
THE APPLE CROP AND LOSSES FROM INSECTS. 
HE APPLE, KING OF FRUITS, has assumed a high rank among American 
agricultural products. In the United States its average monetary value 
over the five-year period 1914-18 has been placed at about $185,000,000,% or 
approximately one-half the estimated worth of the potato crop. The financial 
success of the apple industry is dependent, however, upon several factors, aud 
among these insects play an important rodle. The annual loss to the apple crop 
through insect ravages is somewhat variable, changing from year to year, not 
only in the large fruit-growing districts but in individual orchards as wel! 
Although it is extremely difficult to estimate the yearly loss due to insects, a 
fairly conservative estimate would place it at about 10 to 20 per cent of the 
crop value, or, at the lower figure, about $18,000,000. To this should be added 
the loss of the trees themselves as the result of infestations of apple-tree borers, 
scale insects, etc., and the considerable amount expended for spraying appa- 
ratus, insecticides, and labor. 
In the present bulletin an attempt has been made to acquaint the fruit grower 
with the general distribution, description, life history, and control of the upple 
insects with which he is likely to be troubled. The orchardist would do wel] 
to study carefully the insects causing important injury, in order that remedial 
measures may be intelligently applied. 
CODLING MOTH.* 
The codling moth, or “apple worm” as it is commonly called, is unques- 
tionably the most serious insect enemy of the fruit of the apple and annually 
destroys or renders unfit for commercial purposes millions of dollars worth 
ot fruit, despite present efforts to control it by spraying. It should hot be 
inferred, however, that spraying measures are ineffective, for it has been 
amply demonstrated that thorough and timely spraying will usually yield 
from 90 to 95 per cent and often more of worm-free fruit, except in some 
of the semiarid regions of the West where this insect is unusually abundant 
and destructive. In the absence of combative measures, the codling moth 
will frequently infest from 25 to 90 per cent or more of the fruit, depending 
upon the locality, seasonal and weather conditions, size of the crop, anil 
other contributing factors. Apples infested with this insect are commonly 
valled ‘““wormy apples” (figs. 1, 2, and 3), but to avoid possible confusion it 
should be borne in mind that this fruit may be wormy through infestation by 
other pests, as the apple maggot (p. 18), lesser apple worm (p. 10), ete. 
Shortly after hatching from the egg, the larva or worm eats its way into 
the flesh of the apple, usually feeding in the direction of the core, and on 
reaching it frequently attacks the seeds. A considerable but variable propor- 
1 Carpocapsa pomonella Linnaeus. 
“Folger and Thompson, The Commercial Apple Industry of North America, p. 3. 1921, 
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