112 BULLETIN 932, IT. S. DEPARTMENT OF AGRICULTURE. 



REVIEW OF SEASONAL-HISTORY STUDIES OF THE CODLING 

 MOTH IN 1915 AND 1916. 



A generalized review of the seasonal-history studies of the codling 

 moth is given graphically in figures 17 and 36 for the seasons of 

 1915 and 1916 respectively. The curves represent approximately 

 the beginning, ending, and crest of activity of the more important 

 biological stages of the insect. 



APRIL MAY JUNE JULY AUGUST 



S JO IS 20 25 30 S 10 IS 20 2530 5 10 /S 20 25 30 S 10 IS 20 26 30 6 10 IS 20 26 



SEPTEMBER OCTOBER ft/MEMBER 



5 10 16 20 2630 6 10/6 20 25 30 S .0 IS 20 26 30 



FlG _ 36. — Diagram of life history of the codling moth in the Grand Valley of Colorado, 1916. 



Pupation of spring brood. — In 1915 pupation commenced April 

 14, reached its maximum May 12, and ended June 8; in 1916 the 

 earliest pupation took place April 16, was at its height May 6, and 

 ceased June 12. 



Emergence of spring-brood moths. — The first moth of the spring 

 brood (1915) emerged May 12, the maximum emergence occurred 

 May 24, and the last moth of this brood issued June 29. In 1916 

 the first spring-brood moth appeared May 10, the maximum emer- 

 gence took place May 24, and the last moth issued June 28. 



