July, 1914.] THE APPLE MAGGOT. 41 



ONE BROOD ONLY. 



In the life history studies carried out in New Hampshire in 

 the last four years there has been no evidence observed of a second 

 brood. In the course of the work large quantities of infested 

 early as well as late apples have been under observation, and 

 the pupse secured from these have been retained under varying 

 conditions for use in further work. In one experiment alone 

 more than 14,000 pupse were under observation and record. 

 In all, large numbers of pupse have thus been recorded, many 

 of which were kept in such surroundings that if any adults had 

 emerged from them the same season in which pupation occurred 

 they would hardly have escaped detection. Considerable quan- 

 tities of such pupse, numbering into the thousands, were kept in 

 closed receptacles in the open, other thousands were within the 

 open-air insectary, where they were entirely surrounded with 

 wire screening. In no case was any emergence observed the same 

 season with any of these many thousands of individuals, where 

 retained under conditions of normal temperature. 



Early in the work, where some pupse were kept in dry soil in a 

 basement room, development was accelerated and flies emerged 

 early. These pupse, however, were in artificial warmth, and 

 in addition the soil containing them was in a glass jar exposed 

 to sunlight, a condition which in itself would materially raise 

 the temperature. Their emergence was considered abnormal. 



The following experiments afford additional evidence. 



In 1912 two lots of infested apples showni in Table 4 as No. 1 

 and No. 3 were secured as early as possible, and kept under 

 observation. 



Lot No. 1 consisted of about three-fourth bushel of August 

 Sweets. These came from the Sunnyside locality, where the 

 season tends to be earlier than at Durham. The fruit was badly 

 infested, and maggots were beginning to mature. These apples 

 were placed on sod August 8, 1912, beneath the shade of a small 

 linden tree at Durham. A large screen-wire cage was placed 

 over them. The cage was kept under careful observation until 

 November 15. No flies emerged in 1912. In 1913 86 adults 

 appeared, as given in detail in Table 4, column 1. 



Lot No. 3 were Early Harvest apples. This variety is one of 

 the earliest of the summer apples, and one of the first to grow 



