CODLING MOTH IN SANTA CLARA VALLEY. 165 



vials. Compared with seasons 1909-10 and 1910-11 this was a very 

 small proportion of moths for the first brood as against those hiber- 

 nating as larvae, for in both these seasons the advantage lay easily 

 with the first brood. According to these data there appears to be an 

 excellent reason to look for a large overwintering emergence in 1912. 



REVIEW OF LIFE-HISTORY WORK OF 1911. 



Similar records on the life history of the codling moth to those kept 

 in 1910 were obtained in 1911. The results of these observations are 

 shown in the diagram, figure 39. Spring pupae were present about 

 February 20 and continued until June 20, reaching the maximum 

 about April 12. Moths began to emerge about March 24 and con- 

 tinued until June 8, with the maximum emergence occurring about 

 May 8. Eggs of the first brood were deposited from March 24 until 

 July 11, with the maximum deposition taking place about May 12, 

 while the first-brood larvae hatched from April 23 until July 26, 

 with the maximum hatching period occurring about May 30. First- 

 brood larvae cocooned from May 25 until August 26, with the maxi- 

 mum cocooning period about June 28. The first-brood pupae were 

 present from June 30 until September 29, with a maximum period 

 about July 28. First-brood moths began emerging July 17 and 

 continued until September 29, the maximum emergence taking place 

 August 16. 



Second-brood eggs were deposited from July 18 until October 4, 

 with the maximum period about August 28, while the larvae hatched 

 between July 30 and October 18, with a maximum hatching about 

 September 4. The second-brood larvae began to cocoon August 14 

 and on throughout the winter, reaching their maximum about 

 September 18. The overwintering part of the first-brood larvae 

 commenced to cocoon about June 12, but the majority of the over- 

 wintering larvae came from the second brood. The life cycle from 

 the time the spring pupae appeared until the last first-brood larvae 

 cocooned occupied a period of six months. 



COMPARISON OF LIFE HISTORY IN 1910 AND 1911. 



From a comparison of figures 31 and 39 it is apparent that the main 

 difference exists in the fact that the 1911 season was about two weeks 

 later all through. This is quite to be expected from the colder and 

 later season of 1911. Table LV shows a comparison of the life 

 histories and various stages of the codling moth in 1910 and 1911. 



