THE CODLING MOTH IF THE YAKIMA VALLEY. 



19 



Length of feeding period, bagged-fruit method. — In Table 16 it will be 

 found that 93 larvae reared by the bagged-fruit method fed an average 

 of 29.75 days. The reason this average is less than that of the 

 stock-jar larva? is that this method was used only for larvae entering 

 the fruit for a period of two weeks, and during the time they were 

 feeding the temperature averaged warmer than it did for the whole 

 period of feeding of the second brood, which is covered by the stock- 

 jar larvae. 



Table 16. — Length of feeding period of larvae, of the second brood of the codling 

 moth, bagged-fruit method, Yakima, Wash., 1919. 



Date of 



entering 



fruit. 



Num- 

 ber of 

 larvse. 



Feeding period in days. 



Date of 

 entering 

 fruit. 



Num- 

 ber of 

 larvee. 



Feeding period in days . 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



July 26 



5 



28.00 



34 



25 



Aug. 3 



6 



29.00 



44 



22 



27 



6 



28.83 



43 



23 



4 



8 



27.38 



39 



17 



28 



4 



31.00 



42 



21 



5 



6 



30.67 



42 



22 



29 



9 



24.89 



33 



21 



6 



7 



29.86 



49 



22 



30 



8 



27.75 



37 



21 



7 



7 



35.29 



45 



22 



31 



9 



24.78 



29 



22 



9 



14 



34.71 



40 



24 



Aug. 2 



4 



35.50 



43 



27 













Total number of larvse 93 



Average length of feeding period in days '_'_ 29. 75 



Maximum length of feeding period in days 49 



Minimum length of feeding period in days 17 



Length of the cocooning period. — Only five larvae of the second brood 

 pupated, all of them being among the earliest to leave the fruit. 

 The cocooning period of these larvae was 5, 6, 7, 9, and 9 days, re- 

 spectively, the average being 7.20 days. 



PTJP.E OF THE SECOND BEOOD. 



Time of pupation. — One larva pupated on August 18, one on August 

 26, and three on August 28. 



Length of the pupal stage. — The pupal stage of these five individuals 

 was 11, 14, 16, 19, and 20 days, respectively, the average being 16 

 days. 



MOTHS OF THE SECOND BROOD. 



Time of emergence. — The five pupae mentioned above produced 

 moths on August 29, September 11, 13, 15, and 16. 



LIFE CYCLE OF THE SECOND GENERATION. 



The life cycle of five individuals of the second generation is given 

 in Table 17 and averages 52.2 days, which is somewhat shorter than 

 that of the first generation. 



Table 17. — Life cycle of the second generation of the codling moth, as observed by 

 rearing, Yakima, Wash., 1919. 



Egg deposition. 



July 15. 

 July 18. 

 July 20 . 

 July 22 . 

 July 27. 



Hatch- 

 ing. 



July 22 

 July 25 

 July 27 

 July 29 

 Aug. 4 



Date of- 



Larvse 



leaving 



fruit. 



Aug. 13 

 Aug. 20 

 Aug. 19 

 ...do.... 

 Aug. 21 



Pupa- 

 tion. 



Aug. 18 

 Aug. 26 

 Aug. 28 

 ...do.... 

 ...do.... 



Emer- 

 gence of 

 moths. 



Aug. 29 

 Sept. 15 

 Sept. 11 

 Sept. 13 

 Sept. 16 



Average... 

 Maximum . 

 Minimum . 



Days required for— 



Incu- 

 bation. 



7.2 



8 

 7 



Feed- 

 ing of 

 larvae. 



21.8 

 26 

 17 



Cocoon- 

 ing. 



7.2 

 9 

 5 



Pupal 

 period. 



16.0 

 20 

 11 



Life 

 cycle. 



45 

 59 

 53 

 53 

 51 



52.2 

 59 



45 



