64 



BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. 



the spring brood of moths, in order to time properly the first cover 

 application of spray. These points were made the subjects of 

 experiments in 1919 and 1920, both on moths of the spring brood 

 and on those of the first brood, and in 1921 on moths of the first 

 brood. 



Moths of the spring hrood. — In 1919, seven cages of moths, each 

 containing approximately 25 individuals, were observed daily, begin- 

 ning at 6 a. m., and observations were made every three hours, 

 except at 3 a. m., during the period from June 3 to June 8, inclusive. 

 The temperature at the time of making each observation was also 

 noted. The results of these observations are given in Table 52, 

 the number of eggs deposited in all the jars for any given period 

 being added together. No eggs were deposited between midnight 

 and 6 a. m., and thereafter the number increased for each period, 

 reaching a maximum of 57.30 per cent of the total during the 3-hour 

 period ending at 6 p. m. Between 3 p. m. and 9. p. m., 80.67 per 

 cent of the total eggs were deposited. 



Table 52.— 



Time of oviposition by codling moths 



of the spring brood, in 



3 -hour 







periods, Yakima, Wash., 



1919 















Date of oviposition. 





3 

 03 

 g 



a 



H 



3 

 O 





June 3 



June 4 



June 5 



June 6 



June 7 



June 8 



oo 



M 



w 



C 



Hour of 



• 









_■ 

















II 



observation. 



bfi 

 be 









CJ2 





b£ 



bo 



« 



bo 





bfi 



be 







C S 







* 





3 





a 





H 





H 



3 





H 



3 





*» 





O 





c 













O 





O 















03 





03 





os 





a 





03 





03 



£S 













© 



© 



© 



p. 



© 



© 



P< 



© 



© 



© 



© 



© 



.a 



© 



a. 



« 



bC 

 03 



t| 





| 



a 



1 



1 



$ 



1 



a 



3 



a 



^ 



1 



£j 



a 



d 



© 

 > 



S 





A 



H 



A 



H 



£ 



H 



K 



H 



'A 



H 



'A 



H 



H 



< 



ft 







 

 7 



24 

 119 



10 

 



51 

 63 

 72 

 76 

 75 

 61 

 58 





 

 

 24 

 66 

 76 

 



57 

 67 

 78 

 81 

 79 

 66 

 61 





 3 

 1 



4 

 41 

 14 



4 



60 

 68 

 79 

 79 

 70 

 57 

 56 





 

 1 

 

 8 

 

 



51 

 59 

 66 

 69 



62 

 52 



4? 





 

 



2 

 9 



1 

 



49 

 61 

 67 

 71 

 66 

 67 

 51 





 

 

 16 

 12 

 3 

 



55 

 65 



71 

 74 

 69 

 54 

 U 







3 



9 



70 



255 



104 



4 



53. 83 

 63.83 

 72.17 

 75.00 

 70.17 



52.00 



0.00 





0.67 



12 noon 



2.02 



3 p. m 



15.73 





57.30 





23.37 



12 midnight 



0.90 



Total 



160 





166 





67 





9 





12 





31 





445 















Total number of 



eggs on foliage. . 



















.. . 394 



eggs on cases. . . 



















51 



Per cent of eggs 



Dn fol 



age. 





















. 88. 54 



In 1920, five cages of moths were used for observations on the 

 time of oviposition, the results of these observations being pre- 

 sented in Table 53. During the time these moths were under special 

 observation they deposited no eggs between midnight and 9 a. m. 

 Thereafter, the number increased for each succeeding 3-hour period 

 until the period ending 6 p. m., during which 40.92 per cent of the 

 total were deposited. Between 3 p. m. and 9 p. m., 68.97 per cent of 

 all eggs were deposited. 



