The Currant Fruit Fly. 195 



sumed, but in other instances, some of the seeds were not injured. 

 In one currant 9 empty seed coats were counted and in addition, 

 the embryos of two seeds were partly devoured. As a general 

 rule, however, less than half a dozen seeds are destroyed in each 

 currant. Within some of the seed coats brown particles may be 

 found and these apparently are the excrement of the maggot. 

 In the pulp, these particles are glued together. The brown mass 

 sometimes contains the exuvia of the larva, the black molted 

 mandibles being conspicuous under a binocular microscope. 



Respiratory Pore. 



Sometimes a small hole is present in the peel of currants 

 (Fig. 13, R) and gooseberries which is apparently used for the 

 purpose of respiration by the maggot. A larva was frequently 

 found in berries with the posterior spiracles near the respiratory 

 pore. This breathing pore is absent in fruit containing larvae 

 in the early stages of development. When the maggot issues 

 from the fruit it usually bores through and enlarges the respir- 

 atory hole, so that berries which show the exit hole usually do 

 not show the breathing pore. Within the respiratory hole of a 

 Chautauqua gooseberry six small oval eggs were found, evidently 

 of some parasite. 



Exit Hole. 



When the larva is full grown it forces its way through the 

 pulp, either cuts a hole through the peel (Fig. 13, E) or enlarges 

 the respiratory pore (Fig. 14, H), and issues from the berry. 

 This exit hole is partly enclosed by the ragged edges of the 

 epidermis (Fig. 15, G) which was severed by the larva. A tun- 

 nel with the wall composed of brown particles can be traced to 

 the exit hole in gooseberries. 



Jumping Habit of Larvae. 



After burrowing out of the fruit, the mature larva often 

 exhiljits a peculiar jumping habit. The maggot first slowly 

 arches its body in a circle (Fig. 13, B) ; the posterior spiracles 

 are next invaginated while the pair of hooked mandibles (Fig. 



