8 



BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. 



MOTHS OF THE SPRING BROOD. 



Time of emergence. — The first moth emerged May 13, about two 

 weeks after the apple trees were in full bloom. Moths continued 

 to emerge until June 19, as shown in Figure 2, with a final straggler 

 on June 26. The maximum period of emergence occurred from May 

 18 to June 5, with a maximum of 85 moths on May 21. On May 

 29 and 30 there was a decided drop in the temperature, resulting in a 

 temporary falling off of the number of moths emerging. Otherwise 

 the emergence curve is fairly regular. 



Oviposition by moths of the spring brood. — Oviposition records were 

 obtained from 579 moths of the spring brood. One lot of moths, 



emerging May 27, 

 began ovipositing 

 the next day, but 

 the interval before 

 oviposition aver- 

 aged 5.53 days, with 

 a maximum of 18 

 days. The interval 

 before maximum 

 oviposition aver- 

 aged 9.93 days, with 

 an average ovipo- 

 sition period of 

 14.67 days and an average time from emergence to last oviposition 

 of 19.2 days. All these data are given in Table 3. It must be borne 

 in mind that these averages are for cages and not for individuals. 

 Some individual averages will be found on page 67. 



Fig. 2. 



-Emergence of the spring brood of moths of the codling moth at 

 Yakima, Wash., 1919. 



Table 3.- 



-Oviposition by codling moths of 



the spring brood in rearing cages, 











Yakima, Wash., 1919. 















Sex. 





Date of— 



Number of days — 

























Total 

 num- 























Ob- 



Num- 

















From 





From 



ber 



ser- 



ber 















Be- 



emer- 



Of 

 ovi- 

 posi- 

 tion. 



of 



va- 

 tion. 



of 

 moths. 



Male. 



Fe- 

 male. 



Emer- 

 gence. 



First 

 oviposi- 

 tion. 



Maxi- 

 mum ovi- 

 position. 



Last ovi- 

 position. 



fore 

 ovi- 

 posi- 

 tion. 



gence to 

 maxi- 

 mum 

 ovipo- 

 sition. 



gence 

 to last 

 ovipo- 

 sition. 



eggs 

 de- 

 pos- 

 ited. 



1 



19 



14 



5 



May 18 



May 21 



May 28 



June 5 



3 



10 



16 



18 



13 



2 



24 



14 



10 



May 19 



June 6 



June 6 



June 16 



18 



18 



11 



28 



10 



3 



26 



18 



8 



May 20 



May 22 



May 26 



June 5 



2 



6 



15 



16 



43 



4 



75 



34 



41 



May 21 



May 23 



June 1 



June 15 



2 



11 



24 



25 



212 



5 



74 



42 



32 



May 22 



May 26 



June 3 



...do 



4 



12 



21 



24 



202 



6 



18 



9 



9 



May 23 



May 31 



June 6 



June 16 



8 



14 



17 



24 



40 



7 



50 



18 



32 



May 24 



May 26 



June 4 



...do 



2 



11 



22 



23 



450 



8 



25 



14 



11 



May 25 



June 1 



June 1 



...do 



7 



7 



16 



22 



157 



9 



74 



35 



39 



May 26 



...do 



June 4 



June 17 



6 



9 



17 



22 



112 



10 



72 



32 



40 



May 27 



May 28 



June 3 



June 14 



1 



7 



18 



18 



493 



11 



43 



16 



27 



May 28 



June 1 



June 4 



June 15 



4 



7 



15 



18 



130 



12 



26 



12 



14 



May 31 



June 7 



June 7 



June 8 



7 



7 



2 



8 



4 



13 



26 



10 



16 



June 1 



...do..... 



June 16 



June 16 



6 



15 



10 



15 



21 



14 



17 



8 



9 



June 2 



June 12 



June 14 



...do 



10 



12 



5 



14 



15 



15 



10 



3 



7 



June 3 



June 6 



June 6 



...do 



3 



3 



11 



13 



5 



Averagt 





5.53 



9.93 



14.67 



19.20 





Maximi 











18 

 1 



18 

 3 



24 

 2 



28 

 8 

























Number of male moths 



Number of female moths 



Total number of moths 



Total number of eggs 



Average number of eggs per female moth . 



279 

 300 

 579 

 1,907 

 6.36 



