62 



BULLETIN 1235, U 



DEPARTMENT OF AGRICULTURE. 



TIME OF DAY MOTHS EMERGE. 



In order to learn at what time of the day most of the moths emerge, 

 observations were made on moths of both the spring brood and the 

 first brood in 1919 and 1920. Certain lots of pupre were observed 

 hourly from 6 a. m. to 6 p. m., inclusive, during the time the moths 

 were emerging in quantities, and a record was kept of the number 

 found at each observation. The records for 6 a. m. include all moths 

 emerging between 6 p. m. and 6 a. m. 



Moths of the spring brood. — In 1919, the hourly emergence of moths 

 was observed from May 21 to June 1 , inclusive, as shown in Table 48, 

 454 moths being recorded. The largest number for any hour emerged 

 between 9 and 10 a. m., 27.8 per cent of the total being recorded for 

 this hour. 



Table 48.- 



Hourly emergence of codling moths of the spring brood from r? a. m. to 

 6 p. m., inclusive, Yakima, Wash., 1919. 





Number of moths emerging at— 



Total 

 num- 

 ber of 



Date of 



emergence 

 of moths. 



A. M. 



P. M. 





6 



7 



8 



9 



10 



11 



12 



1 



2 



3 4 



5 









May21 



May 22 



May 23 



May 25 



May 26 



Mav 27 



May 28 



May 31 



June 1 





 

 

 

 

 

 

 

 









 

 

 

 

 

 

 







8 

 

 

 

 5 

 

 

 



3 



27 

 

 

 8 



12 

 

 

 



25 



18 



1 



2 



31 



19 



17 



3 



10 



21 

 10 

 3 

 5 

 15 

 15 

 10 

 16 

 8 



10 

 6 



5 



13 

 12 

 9 

 5 

 7 



6 

 4 

 6 

 10 

 3 

 3 

 3 

 2 

 



5 

 2 

 

 9 

 1 

 5 

 

 

 1 



1 

 

 

 

 

 3 

 

 



2 

 2 

 

 4 

 2 

 1 

 

 

 



1 

 

 

 

 



1 

 1 





 





 

 

 2 

 1 

 

 

 

 



SO 

 7S 

 17 

 37 

 74 

 73 

 43 

 26 

 26 



Total... 

 Percent 





 0.0 





 0.0 



13 

 2.9 



50 

 11.0 



126 

 27.8 



103 

 22.7 



74 

 16.3 



37 

 8.1 



23 

 5.1 



11 11 

 2. 4 2. 4 



3 1 3 | 454 

 0.7 J 0.7 



In 1920, the hourly emergence of spring-brood moths was observed 

 from May 26 to 31, inclusive, records being made of 284 moths. It 

 will be seen in Table 49 that the largest number (32.0 per cent) emerged 

 between 10 and 11 a. m. In both seasons a large majority of the 

 moths emerged between 9 a. m. and noon, 66.8 per cent being recorded 

 in 1919, and 65.5 per cent in 1920. In neither year did any moths 

 emerge between 6 p. m. and 7 a. m. 



Table 49. 



-Hourly emergence of codling moths of the spring brood from 6 a. m. 

 6 p. m., inclusive, Yakima, Wash., 1920. 



to 





Number of moths emerging at— 



Total 

 num- 

 ber of 



Date of 

 emergence 

 of moths. 



A.M. 



P.M. 





6 



7 



8 



9 



10 



11 | 12 



1 



i 



3 



4 



5 



6 





May 26 



Mav 27 



May 28 



May 29 



May 81 





 

 

 

 





 





 

 





 

 

 

 





 

 



1 

 5 



3 

 20 

 3 



2 

 19 



25 

 8 

 8 



1 

 49 



25 

 4 

 2 

 2 



IS 



13 

 3 

 9 

 6 



1 



5 

 9 



1 

 2 



5 

 5 

 6 

 

 3 





 3 

 3 







4 





 2 

 

 

 





 

 

 

 4 



76 

 54 

 39 

 13 

 102 



Total... 

 Per cent 



o 



0.0 





 0.0 



6 

 0.0 2. 1 



47 i 91 

 16. 6 32.0 



4S 

 16.9 



32 25 

 11.3 ' 8.8 



19 

 6.7 



10 2 



a. b o. 7 



4 

 1.4 



2S4 



