THE CODLING MOTH IK MICHIGAN. 



33 



and summer. To a certain extent the 1911 life-history studies con- 

 stitute a test upon the 1910 investigation and in addition show the 

 behavior of the codling moth under the above climatic conditions. 



In the presentation of the observations made during 1911 on the 

 codling moth the same plan has been followed as for 1910, and many 

 of the details concerning methods and tabulation previously described 

 apply equally to the 1911 studies. 



Table XXXII. — Time of pupation in the spring of 1911. 



Date of 



Number 



Date of 



Number 



Date of 



Number 



Date of 



Number 



pupa- 



of 



pupa- 



of 



pupa- 



of 



pupa- 



of 



tion. 



pupae. 



tion. 



pupae. 



tion. 



pup88. 



tion. 



pupae. 



May 9 



1 



May 22 



10 



June 2 



2 



June 14 



3 



May 11 



1 



May 23 



8 



June 3 



2 



June 15 



1 



May 12 



1 



May 24 



8 



June 4 



3, 



June 16 



1 



May 14 



6 



May 25 



7 



June 5 



5 



June 17 



3 



May 15 



7 



May 26 



5 



June 6 



4 



June 19 



2 



May 16 



2 



May 27 



8 



June 7 



2 



June 21 



1 



May 17 



8 



May 28 



9 



June 8 



2 



June 22 



1 



May 18 



12 



May 29 



6 



June 9 



7 



June 26 



1 



May 19 



16 



May 30 



7 



June 10 



6 







May 20 



14 



May 31 



11 



June 11 



4 







Mav 21 



11 



June 1 



3 



June 13 



1 







Total pupae, 212. 



SOURCE OF REARING MATERIAL. 



The rearing material in the spring of 1911 consisted of wintering 

 larvae, which in a normal way had entered hibernation the previous 

 season. Practically all of the larvae were from band records and 

 represented the normal proportion of both first-brood and second- 

 brood larvae. The wintering cocoons were made between narrow 

 strips of wood (fig. 4) and in pieces of corrugated paper (fig. 17). 

 During the winter larvae were kept in an outdoor shelter. 



WINTER- KILLED LARVAE. 



The percentage of larvae killed by cold during the winter proved to 

 be equally as high during 1911 as observed in 1910. After the com- 

 pletion of the different band-record observations the results show the 

 following percentages of winter-killed larvae: 



Per cent. 



New Richmond band records 38. 1 



Saugatuck band records 30 



Lake Shore band records . . . .* 27. 5 



From these figures should be substracted a small number of larvae 

 injured in the course of transportation from the field to the laboratory. 

 Those from New Richmond showing the highest percentage of mor- 

 tality were sent in boxes through the mail and suffered more or less 

 under transportation. 1 The larvae from the Lake Shore and Sauga- 



1 During 1911 an improvement was made in the method of shipping the larvae from the distant 

 localities of the band records, by the use of mailing tubes (see page 61 and fig. 17). 



