THE CODLING MOTH IN MICHIGAN. 



23 



and the filial average for the various experiments on separate stages 

 averaged 51.6 days. 



The wintering larvse of the first brood, which complete their life 

 cycle the following spring, have not been included in the considera- 

 tion of the life cycle of the first generation. 



THE SECOND GENERATION. 



SECOND BROOD OF EGGS. 



Length of incubation. — On an average the second brood of eggs 

 (Tables XXIV and XXV) required 7.5 days for hatching, which is 

 one day longer than was found necessary for those of the first brood. 

 The maximum length of time for incubation was 11 days, the mini- 

 mum 6 days. The red ring became first visible from three to four 

 days after egg deposition and the black spot two days before hatching. 



Table XXIV. — Length of incubation of the second brood of eggs laid in rearing cages, 



Douglas, Mich., 1910. 



No. of 



obser- 

 vation. 



Date of— 



Duration of— 



. Egg 

 deposi- 

 tion. 



Appear- 

 ance of 



Appear- 

 ance of 



Hatch- 



Red 



Black 



Incu- 



red 



black 



ing. 



ring. 



spot. 



bation. 







ring. 



spot. 





















Days. 



Days. 



Days. 



1 



Aug. 2 



Aug. 5 



Aug. 10 



Aug. 12 



3 



8 



10 



2 



...do 



...do 



...do 



Aug. 13 



3 



8 



11 



3 



Aug. 3 



...do 



Aug. 9 



Aug. 11 



2 



6 



8 



4 



Aug. 4 



Aug. 10 



Aug. 11 



Aug. 13 



6 



7 



9 



5 



...do 



...do 



...do 



Aug. 14 



6 



7 



10 



6 



Aug. 6 

 Aug. 7 







...do 







8 



7 



"Aug". "l2" 



Aug. 14 



Aug. 15 



...... 



7 



8 



8 



...do 



...do 



...do 



Aug. 16 



5 



7 



9 



9 



Aug. 8 



Aug. 13 



...do 



Aug. 15 



5 



6 



7 



10 



...do 



...do 



...do 



Aug. 16 



5 



6 



8 



11 



Aug. 9 



Aug. 12 



...do 



...do 



3 



5 



7 



12 



...do 



...do 



...do 



Aug. 17 



3 



5 



8 



13 



Aug. 10 



Aug. 14 



Aug. 16 



...do 



4 



6 



7 



14 



Aug. 11 



...do 



...do 



...do 



3 



5 



6 



15 



...do 



...-do...... 



...do 



Aug. 18 



3 



5 



7 



16 



Aug. 12 



Aug. 15 



Aug. 17 



...do 



3 



5 



6 



17 



...do..... 



...do 



...do 



Aug. 19 



3 



5 



7 



18 



Aug. 13 



Aug. 16 



Aug. 18 



...do 



3 



5 



6 



19 



...do 



...do 



...do 



Aug. 20 



3 



5 



7 



20 



Aug. 14 



...do 



...do 



...do 



2 



4 



6 



21 



Aug. 15 



Aug. 17 



Aug. 19 



Aug. 21 



2 



4 



6 



22 



...do 



...do 



...do 



Aug. 22 



2 



4 



7 



23 



Aug. 16 



Aug. 18 



Aug. 21 



...do 



2 



5 



6 



24 



...do 



...do 



...do..... 



Aug. 23 



2 



5 



7 



25 



Aug. 17 



Aug. 19 



...do 



...do 



2 



4 



6 



26 



...do 



...do 



...do 



Aug. 24 



2 



4 



7 



27 



Aug. 18 



Aug. 21 



Aug. 23 



...do 



3 



5 



6 



28 



Aug. 19 



Aug. 22 



Aug. 24 



Aug. 25 



3 



5 



6 



29 



Aug. 20 



Aug. 23 



Aug. 25 



Aug. 27 



3 



5 



7 



30 



Aug. 21 



...do 



...do 



...do 



2 



4 



6 



31 



...do 



...do 



...do 



Aug. 28 



2 



4 



7 



32 



Aug. 22 



Aug. 25 



Aug. 27 



...do 



3 



5 



6 



33 



...do 



...do 



...do 



Aug. 29 



3 



5 



7 



34 



Aug. 23 



Aug. 26 



Aug. 28 



...do 



3 



5 



6 



35 



...do..... 



...do 



...do 



Aug. 30 



3 



5 



7 



36 



Aug. 24 



Aug. 27 



Aug. 29 



...do 



3 



5 



6 



37 



...do 



...do 



...do 



Aug. 31 



3 



5 



7 



38 



Aug. 25 



Aug. 29 



Aug. 31 



Sept. 2 



4 



6 



8 



39 



...do 



...do 



...do 



Sept. 3 



4 



6 



9 



40 



Aug. 26 



Aug. 30 



Sept. 1 



...do 



4 



6 



8 



41 



...do 



...do 



Sept. 4 



4 



6 



9 



42 

 43 



Aug. 28 

 ...do 



Sept. 2 



" Sept" "i" 



Sept. 5 

 Sept. 6 



5 

 5 



7 

 7 



8 

 9 



44 



...do 



'.'.'.do".'.'. 



'.'.'.do'.'.'.'.'. 



Sept. 7 



5 



7 



10 



45 



Aug. 29 



Sept. 3 



Sept. 5 



Sept. 6 



5 



7 



8 



46 



...do do 



...do 



Sept. 7 



5 



7 



9 



Average 



3.4 



5.5 



7.4 



Maximum . . 



6 



8 



11 



Minimum 



2 



4 



6 



