THE CODLING MOTH IN MICHIGAN. 



29 



Whenever possible, winter varieties of apples have been used for 

 the band records to test the extent of infestation of the second-brood 

 larvae. This was not entirely possible in case of the Lake Shore and 

 the New Richmond experiments because of the great scarcity of fruit 

 during 1910, so that in these localities summer and fall varieties were 

 used, in addition to winter varieties. The apple trees of the Sauga- 

 tuck band experiments consisted of the following varieties: Three 

 Baldwin trees, one Greening tree, two Golden Russet trees, and one 

 crab apple tree. Through the courtesy of Mr. Herman Schultz, of 

 East Saugatuck, Mich., five of these trees were placed free of charge 

 at the disposal of the station. 



The apple trees were prepared for the band experiment in the usual 

 way. The loose and rough bark was scraped off from the trunk and 

 main branches. Cracks and crevices and decayed hollows in the 

 trees were plastered over with cement. A considerable amount of 

 dead wood had to be removed from several of the trees before these 

 could be used. A 4-ply burlap band about 5 inches wide was placed 

 around the trunk of each tree and about 2 feet from the ground. 

 Sometimes it was necessary to place additional bands around the 

 main branches on badly damaged trees (fig. 9), but as a rule a single 

 band was found to be sufficient. 



The bands were examined every three days and the larvae collected 

 from each orchard were brought to the laboratory for further obser- 

 vations. The details pertaining to these records will be found in 

 Tables XXVIII to XXXI. 



Table XXXI. — Summary of Lake Shore, Saugatuck, and New Richmond, Mich., hand 



record experiments of 1910. 



Observations. 



Lake Shore. 



Saugatuck. 



New Richmond. 



Total. 



Per cent. 



Total. 



Per cent. 



Total. 



Per cent. 





985 



262 

 377 

 639 

 75 

 271 

 860 

 262 

 598 

 125 



100.0 



41.0 

 59.0 

 64.8 

 7.6 

 27.5 

 87.3 

 30.5 

 69.5 

 12.7 



788 



201 

 313 

 514 

 37 

 237 

 577 

 201 

 376 

 211 



100.0 



25.5 

 39.7 

 65.2 

 4.7 

 30.1 

 73.2 

 34.8 

 65.2 

 26.8 



543 



153 

 137 

 290 



42 

 207 

 479 

 153 

 326 



64 



100.0 



Moths emerging: 



1910 



28.2 



1911 



25.2 



1910-1911 



53.4 





7.7 





38.1 





88.2 



Transforming larvae of the first brood » 



31.9 

 68.1 





11.8 







On examining the curves of figure 10, showing the results of the 

 band experiments, it will be noted that the two broods of larvae 

 overlap and can not be definitely determined from these experiments 

 alone. With special reference to the Saugatuck experiments the 

 hypothetical curves in figure 10 which have been drawn to repre- 

 sent the two broods are based on the following considerations: The 



