THE CODLING MOTH IN MICHIGAN. 



side against the celluloid more or less uncovered, so that the insects 

 could be observed within their cocoons without disturbing the latter. 

 Some larvae, however, particularly when exposed to too much light, 

 would line with silk the side of the cocoon against the film. The diffi- 

 culty in such cases was overcome by cutting in the film over the 

 cocoon a small lobe or flap which could be gently lifted for the neces- 

 sary exposure. This device is illustrated in figure 4. The upper 

 figure shows the lower side with numbers corresponding to the posi- 

 tion of the cocoons within. In the central figure several larvae anil 

 cocoons are seen protected by the celluloid film. The two strips of 

 wood are held together by a pair of common paper clips which have 

 been bent and adjusted to the shape desired. 



b 1 12 IS IS 21 24 



June 



FiG.5.— Diagram showing time of spring pupation of the codling moth in 1910, at Douglas, Mich. (Original.) 



Time of pupation. — Owing to the very warm weather during the 

 spring, pupation had commenced by April 15 (see fig. 5). However, 

 with a change to cold weather that followed, pupation was inter- 

 rupted until the latter part of May, and most of the larvae pupated 

 during the brief period from May 19 to May 31. The last pupa of 

 this brood appeared on June 23. (See Table V.) 



Table V. — Pupation period/or the codling moth in the spring of 1910, at Douglas, Mich. 



