CODLING MOTH IN NORTHWESTERN PENNSYLVANIA. 



93 



The incubation period ranged from 6 to 16 days, with an average 

 of 9.47. In the time of appearance of the red ring, the range varied 

 from 1 to 4 days, with an average of 2.4 days. The black spot 

 appeared on an average 7.66 days after egg deposition, and hatching 

 generally took place from 1 to 2 days after the black spot had been 

 observed. (Tables XXIX and XXX.) 



Table XXIX. — Incubation periods of second-brood eggs. Summary of Table XX VIII. 



Appearance of red 



Appearance of 

 black spot. 



Total incubation 



ring. 



period. 





Number 





Number 





Number 



Number 



of 



Number 



of 



Number 



of 



of days. 



observa- 



of days. 



observa- 



of days. 



observa- 





tions. 





tions. 





tions. 



1 



6 



5 



4 



6 



1 



2 



32 



6 



26 



7 



12 



3 



30 



7 



19 



8 



20 



4 



3 



8 



4 



9 



16 







9 



1 



10 



7 







10 



3 



11 



2 







11 



8 



12 



4 







12 



7 



13 

 14 

 15 

 16 



5 

 4 

 2 



1 



Table XXX. 



■Incubation periods of second-brood eggs, 

 and XXIX. 



Summary of Tables XX VIII 



Observations. 



Number of days— 



For appear- 

 ance of 

 red ring. 



For appear- 

 ance of 

 black spot. 



For incu- 

 bation. 





2.4 

 4 



1 



7.66 

 12 

 5 



9.47 

 16 

 6 



Maximum 







Eggs deposited from September 15 to September 22, inclusive, 

 failed to hatch because of prevailing cold weather. 



SECOND-BROOD LARV.E. 



Time of hatching. — The extent of the hatching period of second- 

 brood larvae can be accurately determined, since eggs were obtained 

 August 6 from the earliest emerging moths and subsequently almost 

 daily until September 22. In the cages the first larvae hatched 

 August 13 and the last September 21; late-deposited eggs, as already 

 stated, failed to develop because of cold weather, which limited the 

 number of the second-brood larvae considerably. 



Feeding period. — From a number of larvae that hatched in the 

 cages, 100, as given in Table XXXI, developed about normally and 

 entered hibernation. 



