THE CODLING MOTH IN MASSACHUSETTS 61 



Pupation. In a normal season, pupation usually commences the second 

 week of July and continues for a montli or six weeks. The greater part 

 of it, however, takes place during the third or fourth weeks of July- The 

 pupal stage lasts on the average ten to twelve days. If the weather is 

 \ery warm, moths may emerge in six to eiglit days. In a few cases, fifteen 

 to sixteen days are passed in this stage, and one record was taken in wliich 

 twenty-six days elapsed before the motli emerged. There is, however, no 

 such irregularity, at this time, in the duration of the pupal stage as has been 

 noted in the studies of spring pupation. This is due very largely to the 

 more stable and uniform weather conditions prevailing during midsummer. 



Transforming and Overwintering Larvae. The relative number of first 

 brood larvae which transform the same season to moths and those which 

 overwinter, is determined very largely by the time they mature and emerge 

 from the fruit. This association of date of maturity and degree of pupation 

 can be seen from tlie following record taken from our life iiistory studies. 



Date larvae emerged from fruit Per cent pupating 



Last of June to first week of July Approximately 100 per cent. 



First week ot July to third week of July Approximately 75 " " 



Third week of July to first week of Aug. Approximately 2.5 " " 

 After first week of August Less than 5 " " 



This explains why in an "early" season such as 192.5, when a large 

 number of larv'ae matured in late June and early July, there followed an 

 unusually large second brood. Conversely in 1926, a "late" season, mature 

 larvae were found to be leaving the fruit late in July, and the second brood 

 proved to be almost negligible. 



Moth Emergence. Emergence at this season is more uniform than in the 

 spring, and there has not been any indication of a second peak of maximum 

 emergence. The first moths usually appear the third or fourth week of 

 July and continue to emerge for the next four or five weeks. They are 

 emerging in greatest numbers during the last week of July and the first 

 ten days of August. This is fairly constant year after year, however "early" 

 or "late" the season has been up to that time. 



Second Generation. 



Eggs. These moths begin to deposit eggs within two to four days after 

 emergence. As in the spring, the eggs are laid singly upon foliage, twigs, 

 and fruit, but a much larger percentage of them are deposited directly on 

 the surface of the fruit than is the case in the first brood. 



The time required for them to hatch averages from five to six days, but 

 there is a slight tendency for this period to lengthen toward the latter 

 part of August and early September when somewhat cooler weather prevails. 



Since young larvae appear in seven to ten days after the first moths 

 emerge, the greater part of this brood of "worms" appears from August 10 

 to 20. Stragglers are found, however, until well into September. 



Larvae. Upon hatching, the young "worms" lose little time in reaching 

 the fruit and burrowing into it. Very many of this brood enter through 

 the side of the apple, usually where it touches a leaf, twig, or other apple. 

 Second brood larvae, as a rule, remain in the fruit longer than do those in 

 the spring, especially in late September and in October. Life history studies 

 showed that the average time spent in fruit was as follows: 



