July, 1914.] THE APPLE MAGGOT. 77 



At the end of each seven days or oftener, a typical lot of apples 

 was chosen for further record, the other lots of that period now 

 being discarded at the close of their seven-day records. The 

 selected lots were now run through a series of similar boxes in 

 which they remained on soil for one-week periods throughout 

 the remainder of the experiments with that variety. The soil 

 in these boxes was sifted for pupse once a week. 



Thus the records obtained show, for each variety, the actual 

 emergence of larvae each day for the first seven days and the 

 emergence weekly thereafter for typical lots; and in addition this 

 record is distinct for the drops of each week from the time when 

 the apples began to fall until the end of the season. 



The detailed results of the experiments are given in Tables 

 8 to 17, inclusive. Summaries from these tables are presented 

 in Tables 18, 19 and 20. 



LARV.ffi ISSUING FROM LATE APPLES REMOVED FROM NORMAL 



CONDITIONS. 



It has frequently been observed that larvae may issue in num- 

 bers from apples of later varieties while such fruit is being held 

 awaiting barreling or storage, especially if subjected to compar- 

 atively high temperatures. Apparently the condition is simply 

 that the fruit is thereby permitted to mellow sufficiently for the 

 maturity of the larvae, a circumstance that may not come about 

 when such fruit remains on soil in the open. 



In 1909, between September 18 and October 13, various small 

 lots of infested fall and winter fruit were brought to Durham. 

 Some apples from each lot were placed in an incubator main- 

 tained at a temperature of approximately 80 degrees, F., while 

 others were placed on soil outdoors. The lots were too small to 

 permit of general conclusions, but with late fruit it was noted 

 that larvae matured and issued in some numbers from lots in the 

 incubator, while from corresponding lots in the open few or no 

 larvae issued. 



MORTALITY OF COMBINED EGG AND LARVAL STAGES. 



The total mortality of this species in the egg and larval stages 

 is often high and, with late drops of hard, winter varieties, may 

 reach 100 per cent. The soft fruit, falling early, furnishes the 



