CODLING MOTH IN NORTHWESTERN PENNSYLVANIA. 95 



The feeding periods for these larvae ranged from 26 to 73 days, 

 with an average of 39.5 days. The feeding periods in the above 

 records are strikingly longer than those obtained for larvae of the 

 first brood. This is probably due to lower temperature, which 

 during the middle of October for 7 days brought the activities of 

 insects to an apparent standstill. 



Time of leaving the fruit for wintering. — In the cages, the first larvae 

 left the fruit September 11, and since these were from the earliest 

 eggs of the first moths, these records must be approximately accurate. 

 The length of feeding for the early larvae of the second brood was 29 

 to 30 days; the larvae hatched August 13, wintering September 11. 

 With these established facts it is thus possible to separate the first- 

 brood and second-brood larvae from the banded trees, which as to 

 time of reaching maturity overlapped considerably. (See fig. 21.) 

 In the fall, during the alternating warm and cold days, larvae appeared 

 under the bands in variable numbers, as recorded in Table XXXIII. 

 The bands were last examined November 13, when 9 larvae were col- 

 lected. In the rearing cages the last larvae emerged November 15. 



Immature larvse at hibernation time. — It is evident from both field 

 and rearing observations that during the latter part of November, 

 when the temperature had already reached 20° F., quite a number 

 of larvae had not yet attained maturity. Of the reared larvae that 

 hatched September 12 several which were only one- third to one-half 

 grown remained in the fruit, while others hatching September 2 1 were 

 only one-fifth to one-sixth grown. 



From the bands several undersized larvae were collected late in the 

 fall, and it will be of interest to know whether or not they are in con- 

 dition to transform the coming spring. With the records in hand it 

 is not possible to give the relative number of immature larvae in the 

 field that failed to enter hibernation places. In the cages, of 133 

 reared larvae 32 remained in the fruit in the fall, and judging from 

 their size it is doubtful if any of them could possibly attain maturity 

 that late in the season. 



BAND RECORDS OF 1909. 



Through the courtesy of Mr. C. E. Luke, of North East, Pa., an 

 apple orchard of 50 trees was obtained, which was particularly well 

 suited for band records. The trees were about 25 years old and, 

 to the owner's knowledge, had never been sprayed and for some time 

 past had received no care. For several years no fruit had been gath- 

 ered from the orchard. It is thus evident that for years the codling 

 moth had developed without interference and existed under natural 

 conditions. In 1909 most of the trees carried a heavy crop of fruit. 



