258 



Journal of Agricultural Research 



Vol. VI, No. 7 



Table VI. — Effect upon i-day-old Mediterranean fruit-fly pupce of refrigeration at 54° to 

 57° F. Pupce placed in refrigeration August 22, ipij 



Of 1,700 pupae one-half day old when placed in refrigeration none 

 emerged within storage until the twenty-fourth day of refrigeration, after 

 which no data were secured. One hundred pupae removed after 24 days 

 of refrigeration produced 2, 27, and 5 adults 4, 5, and 6 days after removal, 

 proving that even among these very young pupae development was not 

 completely arrested. Out of two lots of 100 pupae each, 46 and 44 pupae, 

 respectively, refrigerated for 22 and 23 days, yielded adults 3, 4, and 5 

 days after removail from storage. 



Data on file bring out an interesting fact that might be expected 

 from the data in Tables VI and VII. The older the pupae when placed in 

 refrigeration, the quicker they develop and produce adults while in 

 refrigeration. Thus in Table VII are recorded data on the development 

 of six-day-old pupae. 



It will be noted that while a few one-day-old pupae require a minimum 

 of 31 days of refrigeration for development, 2 six-day-old pupae com- 



