THE CODLING MOTH IN MICHIGAN. 31 



the maximum occurred August 8, in the Saugutuck orchard July 31, 

 and in the New Richmond orchard July 18. It will not be possible 

 to compare the dates for the appearance of first larvae of the first 

 brood, since the New Richmond experiments commenced slightly 

 after the larvae began to appear. 



At the Lake Shore band experiments larvae were collected in great 

 numbers during the month of August, whereas at New Richmond 

 only a few were obtained. There is only a slight difference in the 

 time of appearance of the earliest second-brood larva' in these locali- 

 ties, winch would indicate the existence of a tendency on the part of 

 the seasonal conditions to become equalized or uniform over the fruit 

 belt at midsummer. At the Lake Shore orchard larva 1 continued to 

 appear one month later than in the New Richmond orchard. Part of 

 this difference was due to the scarcity of fruit at New Richmond, but 

 also partly because of prevailing higher temperature during the fall 

 near the lake, which prolonged the season in the latter locality. 1 

 Though limited in scope, the results of these band experiments show 

 that the codling moth varies in the time of its development in these 

 three localities in close relation to existing climatic conditions, thus 

 indicating that the insect must be governed by the same climatic con- 

 ditions that govern the plants, and it must be due to this fact that 

 we find a corresponding difference in the time of activity of the 

 insect in the spring, as is noted in the time of blossoming of apples 

 in the different sections of the fruit belt. 



Of the total number of larvse of the Saugatuck band experiment 

 73.2 per cent pertained to the first brood and 26.8 per cent to the 

 second brood. Of the first-brood larvae 34.8 per cent transformed 

 the same season, and 65.2 per cent wintered in the larval stage. Of 

 the total number of larva?, 25.5 per cent developed into moths in 

 1910 and 39.7 per cent in 1911. Parasitism by Ascogaster carpo- 

 capsse affected 4.7 per cent, and 30.1 per cent died during the winter, 

 killed by cold. 



SUMMARY OF SEASONAL-HISTORY STUDIES OF 1910. 



Figure 11 represents graphically the main results of the seasonal- 

 history studies of 1910 and can better be appreciated from the 

 diagram than by description. 



Except for the prolonged pupal period during the very abnormal 

 spring of 1910 the insect developed fairly normally so that from the 

 point of view of the activities of the codling moth the season may 

 be taken to have been about average. 



1 For a more thorough tost, records should be taken on temperature, time of blossoming of apples, and 

 tin..' of emergence of spring brood of moths in the different sections in the fruit belt. 



