54 



BULLETIN 932, U. S. DEPARTMENT OF AGRICULTURE. 



Table XXXIV.— Time of deposition, length of incubation, and time of hatching 

 of eggs of the first brood of the codling moth, Grand Junction, Colo., 1916 — 

 Continued. 



Obser- 

 vation 



No. 



Num- 

 ber of 

 eggs de- 

 posited. 



Date — 



Number 



of eggs 



hatched. 



Appearance of— 



Incu- 

 bation 

 period. 



Deposi- 

 ted. 



Red ring. 



Black 

 spot. 



Hatched. 



Red 

 ring. 



Black 

 spot. 



77 

 78 

 79 

 80 

 81 

 82 

 83 

 84 

 85 



Total. 



35 

 3 

 3 



15 



8 



June 28 

 June 29 

 June 30 

 July 1 

 July 2 



June 30 

 July 1 

 July 3 



...do 



July 4 



July 3 

 July 4 



July 4 

 July 5 



12 

 1 





 9 

 5 

 2 

 

 1 

 



Days. 

 2 

 2 

 3 

 2 

 2 



Days. 

 5 

 5 



5 

 5 



Days. 



7 

 6 

 

 6 

 6 

 7 

 

 6 

 



July 6 

 July 7 



July 7 

 July 8 

 July 9 



4 

 1 

 2 



July 3 

 July 5 



July 7 











July 8 



July 10 



July 11 



3 



5 













8,774 



6,597 









| 













Aver 





2.62 



10 



1 



6.68 

 11 



5 



7.32 

 14 

 6 



Max 

 Man. 

















Length of incubation. — The length of incubation and embryolog- 

 ical changes of eggs of the first brood are given in Table XXXIV 

 as follows : Average number of days from date of deposition to the 

 appearance of the red ring 2.62 days, maximum 10 days, minimum 1 

 day; average appearance of the black spot from time of deposition 

 6.68 da3 T s, maximum 11 days, minimum 5 days; average incubation 

 period 7.32 days, maximum 14 days, minimum 6 days. 



Larvae of the First Brood. 



Time of hatching. — The time of hatching of eggs of the first brood 

 will be found in Table XXXIV. The first eggs of this brood 



hatched June 1; the 

 last, July 11. Thus 

 the period of incu- 

 bation extended over 

 one month, the maxi- 

 mum number hatch- 

 ing on June 16, or 

 15 clays after the 

 first larvae appeared. 

 The rate of hatching 

 is shown diagram- 

 matically in figure 

 21, in which it will 

 be noted that the 

 majority of the 

 larvae hatched about 

 the middle of the 

 hatching period. 



Length of the feeding period, stock-jar method. — The summarized 

 account of the length of the feeding period of 817 larvae of the first 



Fig. 21. — Time of batching of eggs of tlie first brood of 

 the codling moth, Grand Junction, Colo., 1916. 



