PROCEEDINGS, 1917. 



37 



MISCELLANEOUS NOTES ON THE APPLE MAGGOT, (1917) 



(Rhagoletis pcmonella Walsh) 



By W. H. Brittain. 



Emergence of Adults 1917: — All the records on this point were taken from in- 

 sects that had spent two years in the rearing cages. They began to emerge on July 19, 

 and continued until the last of August. It is interesting to note that thirty per cent of 

 the entire emergence takes place in the second year, a habit that would enable the insect 

 to live through a total crop failure of its food plants. The pupal mortality varies 

 greatly but it is always very high. Thirty three per cent is the highest emergence re- 

 corded, while the lowest is 5.5 per cent. 



The accompanying table and chart give all the details. 



EMERGENCE OF ADULTS IN 1917 FROM OUT OF DOOR CAGES. 



