34 



BULLETIN 1235, t T . S. DEPARTMENT OF AGRICULTURE. 



LARVAE of the second brood. 



Time of hatching. — Second-brood larvae were hatching during .a 

 period of over 10 weeks, beginning August 2 and ending October 13. 

 The maximum period of hatching extended from August 6 to Sep- 

 tember 6, with an actual maximum on August 12, as shown in Figure 

 19. 



Length of feeding period, stock-jar method. — Table 31 shows the 

 average feeding period of 594 larvae reared by the stock-jar method. 



Table 31. 



-Length of feeding -period of larvae of the second brood of the codling moth, 

 stock-jar method, Yakima, Wash., 1920. 







Feeding period in days. 







Feeding period in days. 



Date of 

 entering 



Num- 

 ber of 







Date of 

 entering 



Num- 

 ber of 





















fruit. 



larva?. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



fruit. 



larvae. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Aug. 3 



3 



22. 33 



25 



17 



Aug. 21 



20 



42.05 



68 



29 



■4 



6 



19.50 



21 



17 



22 



22 



39.36 



60 



25 



5 



14 



24.14 



33 



17 



23 



27 



44.11 



65 



25 



6 



30 



26.73 



44 



17 



24 



23 



44. 13 



63 



24 



7 



12 



26.08 



36 



20 



25 



10 



45. 10 



61 



31 



S 



35 



29.43 



49 



18 



26 



15 



37.13 



48 



22 



9 



53 



30.21 



60 



20 



27 



4 



43. 75 



61 



32 



10 



43 



29.63 



54 



18 



28 



5 



40.60 



59 



33 



11 



39 



34.59 



70 



22 



29 



1 



41.00 



41 



41 



12 



29 



28. ()() 



48 



23 



30 



6 



40.17 



53 



33 



13 



28 



36. 36 



70 



24 



31 



7 



44.14 



0/ 



30 



14 



38 



35.11 



64 



18 



Sept. 1 



3 



47.00 



56 



29 



15 



22 



37.68 



51 



22 



2 



4 



46.00 



53 



35 



16 



20 



35. 70 



55 



18 



3 



11 



4S. 55 



Ol 



35 



17 



9 



39.22 



49 



27 



4 



3 



50.67 



54 



48 



18 



s 



41. 38 



71 



29 



o 



11 



50.00 



62 



40 



19 



12 



31.83 



43 



26 



6 



3 



49.33 



54 



44 



20 



17 



38.71 



59 



28 



8 



1 



48.00 



48 



48 



Total number of larvae 594 



Average length of feeding period in days 35. 30 



Maximum length of feeding period in days 71 



Minimum length of feeding period in days 17 



Length of feeding period, bagged fruit method. — In Table 32 will be 

 found the feeding period of 106 larvae reared by the bagged-fruit 

 method. 



Owing to the late season, none of the second-brood larva reared in 

 L920 pupated, hence it is not possible to give any further data for 

 this year. 





