42 



BULLETIN 189, U. S. DEPAETMENT OE AGRICULTURE. 



NUMBER OF FIRST-BROOD LARV.E TRANSFORMING FIRST SEASON. 



Table XXXIX shows the numbers of transforming and wintering 

 band-collected larvae of the first brood for several localities. These 

 data are tabulated for their value in determining the relative size of 

 the second brood of larvae. 



Table XXXIX. — Number of first-brood larvae of the codling moth transforming to moths Ij 



the first season. 



Locality. 



Year 



Number of 

 first-brood 



larvae 

 living to 

 transform. 



Number of 

 first-brood 



larvae 

 transform- 

 ing first 

 season. 



Per cent 

 transform- 

 ing first 

 season. 



Number of 

 first-brood 



larvae 

 wintering. 



Charlottesville, Va 



Do 



Hagerstown, Md 



Do 



Fishersville, Va 



Winchester, Va 



Do 



Keyser, W. Va 



French Creek, W. Va. 



Do 



Pickens, W. Vtf 



Total. 



1912 

 1913 

 1912 

 1913 

 1912 

 1912 

 1913 

 1911 

 1911 

 1912 

 1911 



259 

 278 

 1,122 

 1,356 

 308 

 266 

 476 

 226 

 202 

 93 

 154 



217 

 269 

 I 17 

 227 

 278 

 228 

 325 

 221 

 201 

 81 



4,740 



2,2S4 



95.37 

 96.76 

 13.19 

 16.74 

 90.26 

 85.71 

 68.28 

 97.78 

 99.50 

 87.10 

 38.31 



48.19 



2,456 



Since an indeterminate number of larvae always die in the jars on 

 account of artificial conditions, only those that lived to emerge as 

 moths are considered in this table. It will be seen that there is a great 

 variation in the percentage of the larvae wintering in the different 

 localities, and that in no case did all the first-brood larvae transform 

 to moths the first season. At Charlottesville, Fishersville, Keyser, 

 and French Creek the proportion transforming the first season was so 

 great as to insure nearly a full second brood of larvae, while at Hagers- 

 town and Pickens the large proportion wintering would indicate only 

 a partial or scant second brood. 



Where the banded orchards were bearing a full crop of fruit and 

 other conditions were favorable for normal development of the larvae, 

 the relative sizes of the first-brood and second-brood band collections 

 support the conclusions to be drawn from the data given in the table. 



EFFECT OF DIFFERENCES IN ALTITUDE AND LATITUDE UPON THE DE- 

 VELOPMENT OF THE CODLING MOTH. 



The stations at which the codling-moth rearing work reported in 

 this paper was conducted comprise a range in altitude of 3,100 feet and 

 in latitude of practically 1° 40 ', or about 115 statute miles. In 

 correlating the data from the various stations an effort has been made 

 to determine whether or not definite differences in altitude and 

 latitude have a corresponding and constant effect on the time of 

 metamorphic changes in this species of insect. The results indicate 



