10 



BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. 



from June 1 to June 8, inclusive, with a maximum deposition of 422 

 eggs on June 4. 



Length of incubation. — Incubation records of 837 eggs are given in 

 Table 5. The earlier eggs required rather more than the average 

 period for incubation, while later, when the temperature was higher, 

 the average period was much reduced. 



Table 5. — Time of deposition and length of incubation of eggs of the first brood of 

 the codling moth, Yakima, Wash., 1919. 



Date of 

 deposi- 



Num- 

 ber of 



Number of days 



from deposition to appearance of— 



Incubation period 



in days. 



Red ring. 





Black spoi 











tion. 



eggs. 











Aver- 



Maxi- 



Mini- 



















Aver- 



Maxi- 



Mini- 



Aver- 



Maxi- 



Mini- 



age. 



mum. 



mum. 







age. 



mum. 



mum. 



age. 



mum. 



mum. 









May 26 



35 



5.00 



5 



5 



11.00 



11 



11 



12.91 



14 



12 



27 



10 



3.00 



3 



3 



9.00 



9 



9 



11.30 



12 



11 



June 1 



61 



3.00 



3 



3 



10.61 



11 



9 



12.65 



14 



12 



2 



38 



3.00 



3 



3 



10.00 



10 



10 



12.00 



12 



12 



3 



161 



3.00 



3 



3 



10.21 



11 



10 



13.02 



14 



12 



4 



218 



5.00 



5 



5 



10.14 



11 



10 



13.96 



15 



13 



5 



76 



5.00 



5 



5 



12.67 



13 



12 



14.47 



16 



14 



6 



34 



6.00 



6 



6 



12.00 



12 



12 



13.29 



14 



13 



7 



33 



7.00 



7 



7 



10.00 



10 



10 



13.18 



14 



13 



8 



45 



8.00 



8 



8 



10.00 



10 



10 



12.51 



13 



12 



9 



2 



8.00 



8 



8 



10.00 



10 



10 



11.50 



12 



11 



11 



14 



7.00 



7 



7 



9.00 



9 



9 



10.43 



11 



10 



12 



36 



7.00 



7 



7 



9.00 



9 



9 



10.28 



11 



10 



13 



10 



7.00 



7 



7 



8.00 



8 



8 



9.90 



11 



9 



14 



10 



6.00 



6 



6 



8.00 



8 



8 



9.30 



10 



9 



15 



6 



6.00 



6 



6 



7.00 



7 



7 



9.00 



9 



9 



16 



3 



6.00 



6 



6 



8.00 



8 



8 



9.00 



9 



9 



17 



39 



6.00 



6 



6 



7.00 



7 



7 



8.05 



9 



8 



18 



1 



5.00 



5 



5 



7.00 



7 



7 



8.00 



8 



8 



20 



2 



4.00 



4 



4 



7.00 



7 



7 



9.00 



9 



- 9 



23 



3 



3.00 



-3 



3 



5.00 



5 



5 



6.00 



6 



6 



837 



4.85 



8 



3 



10.17 



13 



5 



12.73 



16 



6 



/SO 



JUNE 



Fig. 4. — Hatching of larvae of the first brood of the codling 

 moth at Yakima, Wash., 1919. 



LARVAE OF THE FIRST BROOD. 



Time of hatching. — First- 

 brood larvas began hatch- 

 ing in the insectary on June 

 7 (fig. 4), and continued 

 until June 29, a total 

 period of 23 days. On 

 June 10, 11, and 12, no 

 larvse hatched, owing not 

 so much to low tempera- 

 tures at this time as to 

 the fact that no eggs 

 were deposited on May 29 

 and 30. The majority of 

 larvae hatched from June 16 

 to 20, inclusive, the maxi- 

 mum of 147 occurring on 

 June 18, 11 days after the 

 first larva hatched. 



Length of the feeding 

 period, stock-jar method. — 



Table 6 gives the length of the feeding period of 135 first-brood larvae 

 (both transforming and nontransformmg) in stock jars (see p. 5). 



