July, 1914.] THE APPLE MAGGOT. 43 



noted was not normal. Further reference to this possibility will 

 be found in the discussion of the length of the period after 

 emergence before egg-laying. 



In the remaining experiment, the fourth, apples were placed 

 under a field cage which was located beneath an infested apple 

 tree, thus affording, unfortunately, opportunity for extraneous 

 results. The months of July and August, 1911, were marked by 

 extreme heat at Ithaca and elsewhere. 



In another part of the same bulletin, page 162, incidental re- 

 cord is made of the fact that adults emerged in September and 

 October in certain other experiments. These were from pupae 

 that were kept in conditions not normal as a feature of the 

 experiments in hand. 



The experiments are interesting, but the evidence appears to 

 the writer insufficient to warrant general assumption that the 

 apple maggot is two brooded. 



Certainly in New Hampshire there is no indication of a second 

 brood, and there is much evidence that none exists. 



INFLUENCE OF TEMPERATURE AND MOISTURE ON RATE OF 



EMERGENCE. 



A suggestion of the possible influence of moisture and of 

 temperature on the rate of emergence of the adults will be found 

 in the detail records for 1911 and 1913 given in Tables 3 and 4, 

 though definite conclusions may not be drawn because of the 

 part that other factors may play. 



In 1911 9 lots were in whole or partial shade and 4 were in 

 the open. Emergence in the former apparently reached its 

 maximum July 12 to 14, with further heavy emergence on the 

 19th and probably on the 18th. In the latter the maximum 

 apparently came July 7 to 9, although there was an apparent 

 increase again on the 18th. Seemingly the period of rapid emer- 

 gence in the cages in shade lasted a few days later than in those 

 exposed to full sunlight. In the records for 1913, however, there 

 is no clear ratio. 



In 1911 no attempt was made to secure flies from the cages 

 during rainfall, since they were found and secured with difficulty. 

 There was, however, an apparent increase in the rate of emergence 

 following rain. In 1913 such flies as could be found and secured 



