530 JOURNAL OF ECONOMIC ENTOMOLOGY (Vol. 9 



during the greater portion of the time. Had they been Hberated 

 under warmer temperatures it is easy to see from the experiments 

 cited in Table I that the longevity would have been materially reduced. 



On December 8, 1914, 750 adults emerged from another portion of 

 the same media as the experiment discussed above, were fed bananas 

 and milk in abundance. Apparently all fed and were in good condi- 

 tion. They were liberated in a large covered cage iii the open and in 

 addition to the food which was ever present they were supplied with 

 shelter consisting of boards, burlap sacks, paper, and excelsior. These 

 were conveniently arranged to allow the adults to obtain protection 

 with little effort. As will be observed in Table I, a minimum of 

 14.5° F. occurred on December 15, and there was a gradual decrease in 

 temperatures until this degree was reached. On January 4, at a 

 maximum of 64° F., only one adult proved to be alive and this died 

 before January 9. These conditions, which seem to have been more 

 favorable than those obtaining in nature, gave a maximum longevity of 

 not more than 32 days. 



From the two experiments cited above we know what longevity to 

 expect under these temperatures and conditions. Let us now con- 

 sider the questions: What are the reaction of adults in nature to 

 temperatures, and what are the effects of these temperatures on adults? 



Reactions of Adults During the Winter to Varying 

 Temperatures 



In a winter experiment to determine the longevity of adults under 

 kitchen and restaurant conditions a number escaped from the cage 

 and were free to visit places of various temperatures. The general 

 tendency was to seek temperatures sUghtly above 60° F., which being 

 higher than that of the caged ones caused them to die much sooner. 

 It is true that the caged adults were always supplied with food, but 

 bananas and peels were placed in portions of the room where escaped 

 adults were observed to congregate. The last fly in the cage lived for 

 54 days, but no living flies could be found in the room and adjoining 

 rooms after 30 days. 



Observations have been made of flies rendered inactive by low 

 temperatures but in no case have I ever observed living adults to 

 remain quiescent for more than a few days. The natural heat of the 

 sun or very slight artificial heat will cause them to become active. 



In cases where adults were subjected to freezing temperatures they 

 were killed, the duration of life depending upon whether or not they 

 had previously fed. Unfed and slightly fed adults died outright, and 

 those which were allowed to feed previously were not capable of with- 

 standing continuous freezing temperatures for three days. Below 



