The Currant Fruit Fly. 183 



out some currant bushes in an isolated locality in the spring- of 

 1913, and two years later the berries were so badly infested that 

 the crop was not picked. The trypetid was also bred from the 

 fruit of a cultivated shrub commonly called the flowering or 

 mountain currant (Rihes alpinum Pursh). 



LIFE HISTORY. 



A brief historical account of the life history of Epochra 

 canadensis, as determined by a number of entomologists in dif- 

 ferent localities, is herewith given. According to Harvey's 

 (1895, p. 116) observations in the field, the time required for the 

 eggs to hatch and the larvae to mature is about three weeks, 

 while the pupal stage extends over a period of about eleven 

 months under Maine conditions. 



Piper and Doane (1898, pp. 5-6) have worked on the life 

 histories of the dark currant fly (Rhagoletis rihicola Doane) and 

 the yellow currant fly (Epochra canadensis Loew) in the State 

 of Washington. These scientists make the following statements 

 concerning the life history of the dark currant fly : "The eggs 

 soon hatch into small whitish, footless larvae or 'maggots' which 

 eat their way toward the center of the berries and there feed 

 until fully grown. In about three or four weeks they are ready 

 to pupate." The pupae "pass the rest of the summer and winter 

 in this state, emerging as adult fiies the following spring," The 

 authors state that the habits and life history of the yellow cur- 

 rant fly are very similar to' that of the dark currant fly. 



Paine (1912, pp. 141-142) gives the following contribution 

 on the life history of the yellow currant fly or gooseberry fruit 

 fly (Epochra canadensis Loew) in the San Francisco Bay region : 

 "After a period of incubation lasting, in the case of specimens 

 taken into the laboratory, for 11 days, the minute larva or mag- 

 got hatches" ***. The larval period was not determined. The 

 pupa remains in the ground for 10 months. 



Egg and Larval Periods Under Laboratory Conditions. 



In 1914, the duration of the &gg and larval stages of Epochra 

 canadensis was determined by the writer, in the different fruits 

 attacked by the pest in Maine under laboratory conditions. The 

 method followed to induce oviposition, was to place a few twigs 



