Aphilotrix Globuli, 41 



find given of this gall. The woody inner gall is marked 

 by regular furrows and ridges. (Fig. 8.) 



Rearing the fly. There is some difficulty in rearing 

 this fly because of the long duration of the larval state. 

 Although the larva is full grown by the end of October 

 it does not enter the pupa state that year. The state- 

 ment that the flies appear in the following spring is 

 founded on error. The larva state continues into the 

 next year, and it pupates in the autumn, and the 

 fly appears in the April following. But if the galls, 

 when collected, are not kept as much as possible in 

 the same condition as if in the open air, it is very 

 difficult to rear the flies. The galls must therefore 

 pass the winter in the open air in the way previously 

 described, and it is only by this means that the larva 

 can be got to undergo its metamorphosis successfully. 

 If the galls are kept in a room the metamorphosis does 

 not take place. I have kept galls with fully developed 

 larvae for several years without obtaining a single fly. 

 From the galls which pass the winter in the open air 

 the flies as a rule emerge in the second, but in some 

 cases not until the third year. Thus from the galls 

 which I collected in October 1876, I obtained the flies 

 in April 1878, but some did not emerge until April 1879. 

 The same peculiarity occurs with several other species 

 which I shall describe later. 



Fly. Size 4 mm. long, head and thorax black, dull, 

 thickly haired ; abdomen very shining, dark above, 

 reddish brov/n below ; antennae dark throughout ; 

 femora reddish brown, but the coxae and tibiae of the 

 middle and hind legs infuscated. 



