84 
BULLETIN" 1476, TJ. S. DEPARTMENT OP AGRICULTURE 
NEW YORK AREAS 
The seasonal occurrence of each stage of the corn borer is usually 
from three to four weeks later in the New York areas than in New 
England. 
Figure 44 represents graphically a general idea of the seasonal 
occurrence of P. nubilalis in New York during the period from 1920 
to 1922, based upon the averages obtained from actual field ob- 
servations in the environs of Scotia and Silver Creek, as well as 
from contemporaneous insectary rearings. Owing to the sparse 
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Fig. 42.- — Seasonal history of the European corn horer in New England during 
1922. Black areas denote per cent of each stage in the field, as determined 
by field counts. Dotted lines show the probable occurrence (in per cent) 
of eggs and young larvae, as determined by plotting rearing records. Dotted 
line following the graph of first-generation larvae indicates the per cent of 
single-generation individuals 
infestation and the consequent difficulty in making field examina- 
tions during the early season, it is believed that the records per- 
taining to the beginning of pupation, adult emergence, and egg 
deposition are a few days later than the actual appearance of these 
stages in the field. 
The records for 1920 were obtained principally from Scotia, and 
for 1922 from Silver Creek, whereas during 1921 complete records 
were obtained from both localities. During 1921 the seasonal oc- 
currence of each stage of the corn borer at Scotia coincided very 
closely with the occurrence of the same stage at Silver Creek. 
