THE CODLING MOTH IN THE YAKIMA VALLEY. 



25 



Table 20. — Length of life of male and female codling moths of the spring brood, 



Yakima, Wash., 1920. 



Male. 



Female. 



Male. 



Female. 



Male. 



Female. 



Length 

 of life. 



Num- 

 ber of 

 moths. 



Length 



oflife. 



Num- 

 ber of 



moths. 



Length 

 oflife. 



Num- 

 ber of 

 moths. 



Length 

 oflife. 



Num- 

 ber of 

 moths. 



Length 

 oflife. 



Num- 

 ber of 

 moths. 



saelSg 



Days. 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 



4 



10 

 6 

 9 

 7 

 9 



20 

 12 

 19 

 13 

 16 

 17 

 20 

 26 

 18 



Days. 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 



2 



8 



3 



5 



4 



6 



12 



11 



15 



18 



16 



23 



26 



' 38 



24 



Days. 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 

 31 



18 

 15 



12 

 12 

 11 

 11 

 4 

 16 

 10 

 8 

 4 

 5 

 6 

 

 4 



Days. 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 

 31 



21 

 33 



17 

 20 

 20 

 16 

 14 

 20 

 12 

 16 

 17 

 12 

 9 

 3 



7 



Days. 

 32 

 33 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 43 

 45 



Total. 



4 

 2 

 2 



4 



4 



2 

 1 

 1 

 3 

 2 

 



Days. 



32 



33 3 



34 1 



35 I 



36 



37 



38 



39 



40 



41 

 43 

 45 1 2 



Total.' 455 



I 



368 



Average length oflife of male moths, 16.65 days; female moths, 17.73 days. 

 Maximum length of life of male moths, 43 days; female moths, 45 days. 

 Minimum length of life of male moths, 2 days; female moths, 2 days. 



THE FIRST GENERATION. 



EGGS OF THE FIRST BROOD. 



Time of egg deposition. — Spring-brood moths began ovipositing 

 May 12, but owing to cold weather very few eggs were deposited 

 before May 31, as shown in Figure 14. From then on eggs were 



/6 21 26 31 



/O /5 20 25 JO 5 /O /S 



Fig. 14.— Time of deposition of eggs of the first brood of the codling moth at Yakima, Wash., 1920. 



deposited daily until July 11, with a maximum on June 18, 14 days 

 later than the 1919 maximum. The temperature curve in Figure 14 

 shows for each day the average temperature for the period between 

 3 p. m. and 9 p. m., as this is the period during which most of the 

 eggs are deposited. 



Length of incubation. — Observations were made on 1,010 eggs for 

 the length of incubation. These and other data on the development 

 of the eggs are given in Table 21. 



