Page 4 



BETTER FRUIT 



November, 



1920 



single brooded. Second generation eggs 

 were being deposited in the field from 

 August 1 up to September. Moths con- 

 tinued to emerge under insectary con- 

 ditions until October 4. With the limit- 

 ing factor of the effectiveness of the 

 calyx spray for controlling "calyx en- 

 try worms" field records showed that 

 80 per cent of the spring generation of 

 larvae entered through the side of the 

 apple, 8 per cent calyx and 12 per cent 

 stem entry. 



1917. The winter of 1916-17 was 

 colder than normal, and again we find 

 a heavy mortality due to low temper- 

 atures, winter mortality being regis- 

 tered as 84 per cent. Larval material 

 collected in the autumn of 1916 was 

 carried over the winter in burlap bands 

 around a tree, two feet from the ground 

 level and in ground cages. Some larvae 

 were carried over winter in glass cyl- 

 inders, which were open at each end 

 and plugged with cotton wool and also 

 in folds of corrugated cardboard. The 

 only larvae that survived the winter, 

 reaching the adult state, in due course 

 were those that were held in ground- 

 level cages. In one locality some of 

 these cages became flooded early in 

 April by melting snow and remained 

 immersed in water for the best part 

 of three weeks, and the larvae con- 

 tained in them survived, while others, 

 which were subject to the varying 

 spring temperatures above ground suc- 

 cumbed. At the time this note was 

 taken it was remarked that flooding 

 orchards in the early spring would be 

 favorable to the development of the 

 larvae. The mortality of over-winter- 

 ing larvae has been noted by many 

 writers on the codling moth and notes 

 have been taken showing that the range 

 may vary from 5 per cent to 81 per cent, 

 according to the locality and the year. 

 In 1917 over-wintering larvae com- 

 menced to form pupae on May 24 and 

 continued until well into June. The 

 spring generation of moths started to 

 emerge on June 20 and continued emerg- 

 ing during July. The season was back- 

 ward and calyx spraying was in prog- 

 ress between June 1 and 13, just fol- 

 lowing the blossoming period of ap- 

 ples. Eggs, from our observations, 

 were laid between June 29 and July 3, 

 incubation lasting from ten to seven- 

 teen days. The first generation larvae 

 that were observed in the field were 

 found on June 29, and they became full 

 grown on July 15. Pupation of the 

 first generation commenced in the field 

 about July 21. Every larvae (94) under 

 observation this year formed pupa and 

 appeared later as a moth. Hence no 

 records are available to show that any 

 portion of the generation was single 

 brooded, although it may be stated with 

 a fair degree of certainty that practi- 

 cally all were double brooded this year. 

 Second generation larvae were in evi- 

 dence in the fruit on August 10, having 

 commenced to appear around the first 

 of the month. The remarkable differ- 

 ences in this year's records are worth 

 noting. The spring opened late, pro- 

 ducing a delayed flight of moths, but 

 the early summer was very warm and 



the Okanagan Valley near Vernon B. C 



dry so that conditions were more than 

 equalized. 



1918. The blossoming period of ap- 

 ples in the Vernon section occurred 

 during the closing days of April this 

 year and calyx spraying was in prog- 

 ress on May 10. The number of over- 

 wintering larvae this year, which were 

 held under observation, was very few; 

 the mortality, however, due to winter, 

 was less than that which occurred in 

 1917 or 1916. Owing to the transfer of 

 our insectary this year some material 

 was interfered with to such an extent 

 that a very imperfect statement can be 

 made as to the actual mortality due to 

 winter. It was judged, however, to be 

 less than 40 per cent. The first spring 

 brood of moths appeared under insec- 

 tary conditions during the first two 

 weeks of June, but doubtless moths 

 were flying in the field during May 

 and until July, judging from the size 

 of the larvae taken in the fruit in the 

 quarantined orchards. Here again, as 

 in 1917, the great majority of the larvae 

 of the first brood preserved to form the 

 second generation, and moths of the 

 latter generation, were freely appearing 

 from July 24 onward. 



1919. The blossoming period of ap- 

 ples was late this year and the first 

 calyx sprays were being applied be- 

 tween May 27 and June 7. Moths of 

 the spring generation were flying late 

 in June and full grown larvae were 

 present and leaving the fruit on July 

 22. The percentage of the larvae, from 

 cage specimens, that proved to be single 

 brooded this year, was about 20 per 

 cent. Of the remainder, moths appeared 

 on August 7 and continued emerging 

 until late in September. Minute second 

 generation larvae were present in the 

 field in fruit on August 10. 



1920. During this present year the 

 spring moth emergence continued from 

 June 3 to 30. The blossoming period 

 of apples took place between May 10 

 and June 1, and calyx spraying opera- 



tions were in order between May 28 

 and June 13. First cover spray, June 

 26 to July 6. Second cover spray, Au- 

 gust 6 to 20. 



Summary of Life History With Spray 

 Dates— 1916. 



Apple blossoming date, May 1-15. 



Calyx spray date, May 15-30. 



Flight spring moths, June 7-July 30. 



Larvae full grown (1st breed) July 18. 



Flight summer moths, August 1. 



Second brood larvae entering applies, 

 August 15. 



1917. 



Apple blossoming date, May 10-30. 



Calyx spray date, June 1-13. 



Flight spring moths, June 20-July 15. 



Larvae full grown (1st brood) July 15. 



Flight summer moths, July 25. 



Second brood larvae entering apples, 

 August 1. 

 Cover spray date, June 28-July 9. 



Third spray date, August 3-13. 

 Band examinations — ■ 



(1) Julv 19-30. 



(2) August 2-19. 



(3) August 28-September 12. 



(4) September 17-22. 



(5) September 24-29. 



(6) October 5-9. 



(7) October 10-15. 



(8) November 10-22. 



1918. 



Apple blossoming date, April 29-May 7. 



Calyx spray date, May 10-25. 



Flight spring moths, May 25-July 1. 



Larvae full grown (1st brood) July 15. 



Flight summer moths, July 24-Au- 

 gust 8. 



Second brood larvae entering applies, 

 August 1. 



Cover spray dates, June 23-29. 

 Band examinations — 



(1) Julv 2-15. 



(2) Julv 17-30. 



(3) August 5-12. 



(4) August 18-September 4. 



(5) September 27-October 3. 



(6) November 6-20. 



