s 



CIRCULAR 356, 17. S. DEPT. OF AGRICULTURE 



Turkish, storage warehouses 25 traps were operated from June 1 to 

 November 13, and in the domestic storage warehouse 20 traps were 

 operated from June 15 to November 13. One trap was operated for 

 each 75,850 cubic feet of warehouse space. The numbers of beetles 

 caught during this period are presented in table 2 and figures 7 and 8. 



900 

 850 

 800 

 750 

 700 

 650 

 600 

 550 

 500 

 450 

 400 

 350 

 300 

 250 

 200 

 150 

 100 

 50 

 



• MAXIMUM TEMPERATURES 

 o MINIMUM TEMPERATURES" 



n— 



n 



_i 





~ 



n 





00 



90 



80^ 



u 

 en 



70? 



< 

 cr 



UJ 



60 5 



UJ 



50 



40 



5 30 



JUNE 



\7_J5l 

 JULY 



14 21 

 AUG. 



21 2 8 6 



SEPT. 



OCT 



20 J3_ 

 NOV. 



Figure 



Average catches of the cigarette beetle, in relation to the temperature and the season, in open- 

 storage warehouses containing Turkish tobacco. Experiment 2. 



These records again show that the population of cigarette beetles 

 was much greater in Turkish than in domestic tobacco. The largest 

 catch in Turkish tobacco, an average per trap of 884,000, was made 

 during a, 7-day interval, September 21 to 28. The largest catch in 

 domestic tobacco, an average of 112,750 beetles per trap, was made 

 during a 21 -day interval, July 24 to August 14. 



Here again it is apparent that temperature alone is not the control- 

 ling factor in beetle migrations. The peak of emergence of the spring 

 brood occurred about June 15 in the Turkish tobacco warehouses, 

 after an average maximum temperature of 88° F. for the 14-day 

 period ended on this date. The largest catch was made during the 

 7-day period ended September 28, when the average maximum temper- 

 ature was 89°. The average minimum temperature for the period 

 ended June 15 was 61°, and for the period ended September 28 it was 



