CODLING MOTH IN SANTA CLARA VALLEY. 181 



fruit remained longer on the tree there would be a complete second 

 brood possible, since so many varieties of apples and pears are picked 

 before the end of September. In 1909 the second generation exceeded 

 the first and this was a cold year, while in 1910 and 1911 the two 

 generations were about equal in numbers, in spite of the fact that 

 the former was a warm, the latter a cold, year. In 1910 there was 

 good reason to expect a large second generation, considerably greater 

 in relation to the first generation than in 1911, but the relative 

 proportions of the two generations was not maintained in 1910. 

 Consequently it may be inferred that the weather does not always 

 exert great influence on the relative sizes of the two generations any 

 more than a large number of individuals of the first brood does on the 

 second. 



The relative number of larvae of the first brood that overwinter 

 varies from year to year, but not entirely owing to influence exerted 

 by the weather or the temperature. 



The larvae of the second brood are present in all but the earliest 

 varieties of fruit, and it is necessary to combat them. 



Weather conditions exert more influence on the spring emergence 

 of moths than on the summer emergence. 



The sex of the moth can be determined in the larval stage by the 

 presence or absence of the two testes, which are black and in the male 

 show through the skin on the dorsum of the eighth segment. 



Three applications of the poison spray are necessary for the control 

 of the codling moth in this locality. The first should be made imme- 

 diately after the petals have dropped from the blossoms, the second 

 should follow from 2 to 4 weeks later, and the third a month or 6 

 weeks after the second. 



ADDITIONAL COPIES of this publication 

 -HL may be procured from the Superintend- 

 ent of Documents, Government Printing 

 Office, Washington, D. C, at 10 cents per copy 



