CODLING MOTH IN NORTHWESTERN PENNSYLVANIA. pW 0 
maturity the larva seeks a hiding place beneath the rough bark of 
the trunk of the tree and constructs a cocoon within which pupation 
takes place about 1 week after the larva left the fruit. Some of the 
larvee do not pupate at this time but winter, and the moths emerge 
the following spring, together with moths from second-brood larve. 
The pupal stage—called the first-brood pupx, though the second set 
of pupe of the season—lasts on an average 12 days. The emergence 
period of this second set of moths, called first-brood moths, begins 
in early August and lasts about 1 month. With the appearance of 
new eggs, resulting from the first-brood moths, the life-cycle of the 
first generation is completed, covering on an average 58 days. The 
second-brood eggs hatch generally within 9 days and the resulting 
larvee feed about 40 days, after which they enter hibernation, making 
cocoons beneath the rough bark on the trunk of the trees. The life- 
cycle of the second generation and part of the first generation is first 
completed with the transformation of the insect the following spring. 
The period covered by the different stages of the two broods for 1909, 
as shown in figure 22, closely represents average conditions. 
The relative number of transforming larve of the first brood is 
variable under different seasonal conditions. 
The relative abundance of second-brood larve depends more 
upon seasonal conditions and food supply than upon the number of 
transforming larvee of the first brood. 
Larve of the second brood are always present in injurious numbers, 
so that measures should be taken to combat the second as well as the 
first brood. 
The time of the emergence of the spring brood of the moths is vari- 
_ able under different seasonal conditions and depends largely upon 
the relative lateness of the spring. 
The time of emergence of the summer brood or first brood of moths 
is fairly constant and generally commences about the 1st of August. 
In the control of the codling moth with poison sprays three appli- 
cations should be made in this section of the country. The first 
application should be made after the blossom period just after the 
petals drop, the second application from 3 to 4 weeks later, and the 
third application from 9 to 10 weeks after the petals drop, or about 
the 1st of August. 
