26 



BULLETIN 932, U. S. DEPARTMENT OF AGEICULTURE. 



and, for this reason, it was impossible to determine from field ma- 

 terial when the last moth of the first brood emerged and when the 



first moth of the sec- 

 ond brood appeared. 

 It is reasonable to 

 infer, however, that 

 the approximate di- 

 vision of the broods 

 occurred during the 

 period of overlap- 

 ping, and for this 

 reason August 19 

 was selected as the 

 end of the emergence 

 of the first brood of 

 moths. The time of 

 emergence of the 

 moths of the first 

 brood from the 

 larvae collected in the 

 Hamilton orchard 

 is given in Table 

 XV and presented 

 graphically in fig- 

 ure 7. According to these data the first moths issued July 10, and 

 emerged in maximum numbers on August 9. 



Table XV. — Time of emergence of codling moths of the first brood, reared 

 from field material, Grand Junction, Colo., 1915. 



Fig. 7. — Time of emergence of moths of the first brood of 

 the codling moth, Hamilton orchard, Grand Junction, 

 Colo., 1915. 



Date of 



Num- 



Date of 



"Num- 



Date of 



Num- 



Date of 



Num- 



emer- 



ber of 



emer- 



ber of 



emer- 



ber of 



emer- 



ber of 



gence. 



moths. 



gence. 



moths. 



gence. 



moths. 



gence. 



moths. 



July 10 



4 1 



July 21 



16 



Aug. 1 



39 



Aug. 12 



75 



11 



22 



22 



17 



2 



31 



13 



79 



12 



50 | 



23 



27 



3 



44 



14 



69 



13 



15 



24 



34 



4 



53 



15 



73 



14 



22 



25 



56 



5 



56 



16 



13 



15 



26 



26 



26 



6 



74 



17 



52 



16 



9 



27 



35 



7 



67 



18 



41 



17 



4 



28 



41 



8 



59 



19 



46 



18 



13 



29 



64 



9 



89 









19 



33 



30 



57 



10 



87 



Total.. 



1,737 



20 



25 



31 



33 



11 



61 







Number of eggs per female moth. — It will be observed in Table 

 XVI that the total number of eggs deposited by the 945 female 

 moths of the first brood was 44,158 or 46.73 eggs per female moth. 

 This average is nearly four times greater than that made by the 

 spring-brood moths (12.59 eggs) owing, doubtless, to the more favor- 

 able climatic factors during the oviposition period of the first-brood 

 moths. 



