22 N. S. ENTOMOLOGICAL SOCIETY 



Oviposition in Fruit in Open. 



Tree Xo. 1. 



11 females and 5 males liberated July 28th 

 16 females and 9 males liberated July 29th 



Aug. 5th, 1 apple, 4 punctures, 3 eggs, larvae 



" 6th, 2 " 8 7 " 1 " 



" 7th, 1 " 6 " 5 " " 



" 8th, 2 " 5 " 2 " " 



Tree No. 2. 



28 females and 36 males liberated Aug. 4th. 



Aug. 13th, 1 apple, 3 punctures, eggs larvae 

 " 17th, 1 " 1 " " " 



It will be seen that the first eggs were laid 7-8 days from 

 the date of hatching and the first and only fertile egg 8-9 day 

 from that time. In the case of the second tree the results are 

 negative. 



It is to be regretted that more data is not available on this 

 point, though such data is difficult to obtain. It is hard to 

 transport the flies any distance without injury and it was not 

 thought advisable to liberate flies in a non-infested community. 

 Furthermore, flies liberated in such situations as we were forced 

 to use, tend to disperse immediately. However, we have one 

 authentic record of a fertile egg deposited in an apple by a fly 

 living under natural conditions, 8-9 days after emerging from 

 the pupa. The results, such as they are, do not indicate that 

 there is much difference between free and captive flies with 

 respect to the duration of the preoviposition period. They in- 

 dicate that in from one to two weeks after emergence the flies 

 may be expected to begin depositing their eggs and that they 

 may continue to do so for about one month. Flies kept in 

 captivity during the course of our experiments have lived for 

 as long as six weeks, though the average was much less. It was 

 observed that the cooler the weather the longer the flies sur- 

 vived. 



From the foregoing data, we understand the necessity in 

 all spraying work, as so often demonstrated by field tests, of 

 having the fruit thoroughly coated with the poison when the 

 flies first appear and of keeping them so covered during the 

 period of maximum emergence. 



