60 



BULLETIN 429, U. S. DEPARTMENT OF AGRICULTURE. 



Larval life in the cocoon. — A comparison of the length of the cocoon- 

 ing period of the second generation with the corresponding period of 

 the first generation shows practically no difference, and a fairly con- 

 stant length of the period may be derived from the figures. Table 

 XLV records the observations with 400 individuals, and while a 

 maximum period is represented by 24 days and a minimum time by 

 2 days, giving a range of variation of 22 days, the results maintain an 

 average period of only 5.6 days for all larvse observed. This period 

 is 0.44 day greater than the length of the cocooning period as observed 

 with larvae of the same generation during the season of 1912. 



Table XLV. — The making of cocoons of the second generation of the codling moth, 



Boswell, N. Ilex., 1913. 



Date of egg 

 deposition. 



Num- 

 ber of 

 indi- 

 vidu- 

 als. 



Length of cocooning period in specified days, being 

 th3 time from leaving the fruit to the time of pupa- 

 tion. 



Aver- 

 age 

 days. 



Mini- 

 mum 

 days. 



Maxi- 

 mum 

 days. 



Total 

 days. 





2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 17 



24 



June 11 



12 



2 



9 



25 



14 



18 



33 



23 



31 



17 



23 



38 



26 



26 



5 



13 



23 



12 



15 



14 



6 



1 



3 



2 



9 





1 



3 



2 

 3 



20 

 6 

 9 



12 

 4 



13 

 5 

 3 

 4 

 2 

 8 



6 



2 



















4.8 

 2.0 

 5 1 



3 



4 



6 



4 



9 



6 



10 



13 



12 



14 



13 



9 



8 



12 



10 



10 



8 



17 



8 



24 

 10 



7 



57 



8 



46 



100 



12 



















13 



5 

 1 

 2 

 4 

 8 

 10 

 10 

 2 

 8 

 13 

 8 

 3 

 2 

 4 

 8 

 6 

 5 

 4 

 2 

 1 

 2 







; 



1 













14 





3 



1 

 2 

 1 

 4 

 2 

 2 

 5 

 6 

 4 

 in 

 4 

 2 

 3 

 7 

 1 

 3 

 1 

 1 















4.0 3 

 5.7 4 

 5.4 2 



15 



1 



1 

 3 

 5 





2 



1 



... 







81 



16 





1 





1 ] 







97 



17 



2 



1 



1 

 1 





■2 









5.8 

 5.9 

 4.6 

 5.5 

 5.6 

 6.3 

 6.9 

 6.0 

 6.0 

 6.5 

 5.0 

 5.1 

 8.9 

 5.1 

 5.1 

 5.0 

 6.0 



4 

 4 

 3 

 3 

 3 

 2 

 4 

 4 

 5 

 3 

 3 

 4 

 5 

 3 

 4 

 5 



192 

 137 

 142 

 94 



18 









i 







19 



... A 











1 



20 



2~ 



1 

 1 

 1 



2 

 3 

 3 



3 

 5 



Y 



1 

 2 



1 



1 

 2 

 2 



2 

 3 



1 



1 















21 















128 

 241 



22 



3 

 2 



2 

 1 

 1 



3 



1 











23 









155 



24 

















158 



25 

















30 



26 





1 

 4 



2 

 2 

 3 







1 







1 





84 



27 



1 













117 



28 

















62 



29 







1 



1 







2 



2 





1 



134 



30 





1 



6 

 2 



1 







71 



July l 



3 













31 





















5 



6 













1 













i " 



5 8 

 4 11 

 2 11 



18 



7 







1 

 1 











1 









7.5 

 6.7 



15 



9 



1 



... 



1 



1 



1 



2 





1 









61 

















400 



3 



19 



111 



115 



62 32 



19 11 



Q 



6 



6 



4 



1 1 1 1 1 5.6 





2,264 

































SECOND BROOD OP PUP.E. 



Length of pupal stage.— The length of the pupal stage of the second 

 generation as compared with that of the first generation is found to differ 

 very little. Of the 400 insects under observation 1 emerged 7 days 

 after pupation had taken place, while the greater length of time was 

 found to be 20 days. An average period of 11.6 days is shown for 

 the entire number observed. Further reference should be made to 

 Table XLVL 



