275 
A daily record of the band collections, life-history observations, and 
_ climatic conditions at Olney in 1917 have been brought together in Table 
38 for ready reference. 
SUMMARY OF THE SEASONAL HISTORY, 1917 
: From the foregoing data, the seasonal history of the codling-moth 
- at Olney can be quite accurately determined (Table 39). 
5 Chart 3 represents in graphic form, the data given in Table 39. 
_ These data are disconnected and meager for the second and third genera- 
_ tions. The position and form of the curved lines in the chart, repre- 
senting the relative number of eggs and young larve of the first genera- 
tion and the number of the different stages of the second and third 
generations, are based upon estimates only, since complete daily records 
were not kept. 
The bulk of the hibernating larve pupated during the unusually 
_ warm period in the third week of April; the bulk of the adults emerged 
_ during the last two weeks of May; the bulk of the eggs of the first 
- generation were laid during the last ten days of May and the first week 
in June; and the bulk of the larve hatched during the first three weeks 
of June. There was no overlapping of the first and second generations 
_ except in the larval stage. 
RELATION OF TEMPERATURE TO THE SEASONAL HIsTORY 
OF THE CoDLING-MOTH 
It has already been shown that there is quite a constant relation 
between the temperatures above 50 degrees when corrected for retarding 
temperatures above 86 degrees and the length of time required to bring 
the insect through the egg, larval, and pupal periods. This applies to all 
_ the periods except the larval period of the hibernating larve. The 
length of time the hibernating larve remain in the cocoon is independent 
_ of the day-degrees which accumulate between the time when hibernation 
_ begins and the winter months. It is found, however, that there is a more 
or less definite relation between the average daily temperatures above 50 
degrees in the spring months and the dates when the first pupz and the 
first adults appear. There is a very great individual variation in this — 
_ respect, as will be seen by referring to the last column of Tables 19 and 
20.* In Table 19, it will be seen that the hibernating larve began to 
_ pupate when the sum of the day-degrees above 50 degrees F. after Janu- 
ary 1 amounted to 115; the accumulations for the others ranged from 
115 to 356, the average being 186. In Table 20 it will be seen that the 
hibernating larve of 1916-1917 began to pupate when the sum of the 
_ day-degrees above 50 degrees F. amounted to 104. The others varied 
_ from 104 to 355, the average being 190. 
* Tables 9-25 follow p. 253. 
