88 



Tart.e IV. — Duration of life of the codling moth inside the cocoon — Continued. 



Aug. 6. 



Aug-. 13. 



Aug. 15. 

 Aug. 20. 

 Aug. 22. 



I)iite of eutering band. 



Number Date 

 of j moths 

 larvte. I emerged. 



1902, 

 Avig. 

 Aug. 

 Aug, 

 Aug. 

 Aug. 

 Aug. 

 Sept. 

 ....do 

 Sept. 

 ....do 

 Sept. 

 ....do 

 Sept. 



Number 

 of moths. 



Time. 



Dai/n. 

 ■ 19 

 20 

 21 

 22 

 23 

 24 

 26 

 19 

 26 

 24 

 23 

 21 

 20 



Total 

 tempera- 

 ture. 



392 

 42.T 

 456 

 485 

 503 

 519 

 558 

 468 

 674 

 604 

 607 

 547 

 633 



Average 

 tempera- 

 ture. 



. The number of larva^ used was 1T<», and the stage varied from 11 to 

 49 days, with a weighted average of 22 days. This average is some- 

 what longer than that secured by other observers, and ma}^ be partly 

 accounted for by the lateness of the season. 



The principal point to be clearly shown is the length of the mini- 

 mum stage, which these experiments show to be not less than 10 to 12 

 davs. 



The time spent in the cocoon ])y the hibernating larv?e varies con- 

 siderabh", but usually lasts about eight months. If the larvae are 

 taken inside and kept where the temperature is higher, moths will 

 sometimes emerge in January or Februar3\ 



INFLUENCE OF TEMPERATURE UPO.N THE DURATION OF THE STAGE. 



Various authors have stated at various times that this stage might 

 be consideral)ly lengthened or shortened bv temperature. Table V 

 shows a preceding table arranged according to the etiective tempera- 

 tures and the lengths of time. 



Tablk Y. — Effectlre temperature and length, of cocoon stage of cocUing moth. 



