THE CODLING MOTH IN THE YAKIMA VALLEY. 



11 



Table 6. — Length of feeding period of larvae of the first brood of the codling moth 1 

 stock-jar method, Yakima, Wash., 1919. 



Date of 



entering 



fruit. 



Num- 

 ber of 

 larvae. 



Feeding period in days. 



Date of 



entering 



fruit. 



Num- 

 ber of 

 larvae. 



Feeding period in days. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



June 14 

 16 

 18 

 19 

 20 

 21 



6 



12 

 26 

 23 

 18 

 18 



25.67 

 25.34 

 24.15 

 24.17 

 23.78 

 23.50 



28 

 28 

 33 

 32 

 30 

 33 



24 

 21 

 20 

 19 



20 

 20 



June 22 

 23 

 24 

 25 

 26 

 28 



5 

 6 

 2 



16 



1 

 2 



25.60 

 22.50 

 22.50 

 21.63 

 30.00 

 19.50 



29 

 24 

 23 

 25 

 30 

 21 



23 

 21 

 22 

 18 

 30 

 18 



Total number of larvae 135 



Average length of feeding period in days 23. 82 



Maximum length of feeding period in days 33 



Minimum length of feeding period in days 18 



Length of the feeding period, bagged-fruit method. — The length of the 

 feeding period of 70 larvae (both transforming and non transforming) 

 reared by the bagged-fruit method (see p. 5) is given in Table 7. 

 Larva) reared by this method occupied a slightly longer time in feed- 

 ing than where reared by the stock-jar method. 



Table 7. — Length of feeding period of larvae of the first brood of the codling moth, 

 bagged-fruit method, Yakima, Wash., 1919. 



Date of 



entering 



fruit. 



Num- 

 ber of 

 larvae. 



Feeding period in days. 



Date of 



entering 

 fruit. 



Num- 

 ber of 

 larvae. 



Feeding period in days. 



Aver- 

 age. 



Maxi- 

 mum. 



Mini- 

 mum. 



Aver- 

 age. 



Maxi- 

 mum. 



Mini- 

 mum. 



June 7 

 9 

 12 

 13 



16 

 17 



3 

 2 

 3 

 6 

 10 

 6 



25.00 

 33.50 

 24.33 

 27.50 

 24.20 

 24.50 



26 

 39 

 26 



29 



27 

 28 



24 

 28 

 22 

 25 

 22 

 22 



June 18 

 19 

 20 

 21 

 23 

 24 



3 

 6 

 15 

 5 

 6 

 5 



25.00 

 21.17 

 25.33 

 23.40 

 24.00 

 25.00 



27 

 24 

 33 

 26 

 27 

 29 



24 

 18 

 22 

 21 

 21 

 22 



Total number of larvae 70 



Average length of feeding period in days 24. 81 



Maximum length of feeding period in days 39 



Minimum length of feeding period in days 18 



Length of the cocooning period. — The cocooning period represents 

 the total time elapsing from the date the larva leaves the fruit until 

 it pupates, although the actual period of constructing the cocoon is 

 necessarily somewhat shorter. In Table 8 will be found data show- 

 ing the cocooning period of 146 transforming individuals of the first 

 brood. 



Table 8. 



-Length of cocooning period of transforming codling moth larvae of the 

 first brood, Yakima, Wash., 1919. 





Num- 

 ber of 

 larvae. 



Cocooning period 



in days. 





Num- 

 ber of 

 larvae. 



Cocooning period in days. 



Larvae left 

 fruit. 







Larvae left 

 fruit. 







Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



July 1 



1 



6.00 



6 



6 



Julv 14 



17 



9.59 



28 



4 



o 



1 



6.00 



6 



6 



15 



22 



8.36 



26 



3 



3 



1 



5.00 



5 



5 



16 



12 



7.25 



26 



5 



4 



1 



4.00 



4 



4 



17 



3 



10.33 



21 



4 



7 



1 



5.00 



5 



5 



18 



3 



4.67 



6 



4 



8 



9 



4.56 



5 



4 



19 



6 



6.67 



15 



4 



9 



8 



5.25 



9 



4 



20 



2 



11.00 



16 



6 



10 



10 



4. SO 



5 



4 



21 



1 



15.00 



15 



15 



11 



11 



4.91 



8 



4 



23 



1 



6.00 



6 



6 



12 



21 



6.81 



25 



4 



24 



1 



6.00 



6 



6 



13 



14 



7.07 



21 



4 















• 116 



6.99 



28 



3 



