The Currant Fruit Fi.y. 197 



Pupal Period. 



After the larvae emerge from the fruit they enter the ground 

 to a depth of from one to three inches to pupate. The pupal 

 period may vary between 10 and 11 months. 



Emergence of Adults. 



Shortly after the adult emerges, the wings are small curled 

 masses projecting from the thorax. While the organs of flight 

 are expanding the fly strokes them on the upper and lower sur- 

 faces with the hind legs and at times separates the two wings. 

 In 15-20 minutes, after the insect has come to rest, the wings 

 are expanded. The opaque appendages first show faint indica- 

 tions of markings which later become more conspicuous as they 

 dry. At this time the wings are held parallel to the long axis 

 of the body and not in the characteristic trypetid manner. The 

 ptylium may still be inflated after the wings are expanded. Nor- 

 mal flight occurs about an hour and a half after the first appear- 

 ance of the fruit flies above the ground. 



Adults with deformed wings were sometimes reared under 

 laboratory conditions. On May 29, 1914, several flies with one 

 or both wings not fully expanded were taken on the ground 

 below currant bushes. 



While the wings are expanding, the segments of the abdo- 

 men are pushed out as far as the membrane connecting the meta- 

 meres will allow. The abdomen of both sexes projects beyond 

 the tips of the recently expanded opaque wings at this time, but 

 does not after the wings are dry. At first the abdomen of the 

 female is curled down so that the seventh tube-like segment 

 containing the ovipositor rests against the substratum, but after 

 the wing pattern becomes more marked, the tube-like segment 

 is turned upward. Finally the membranes between the meta- 

 meres become invaginated, thus pulling the segments into their 

 normal position. The female may now draw the end of the ovi- 

 positor along the substratum and expel a trail of liquid from the 

 egg-laying organ. A red spot on each side of the fifth abdomi- 

 nal segment is present in the male upon emergence but this is 

 absent in the female. 



Dates of emergence of adults. — ^To ascertain the dates of 

 emergence of Epochra canadensis, a cage (height 38, length 60, 



