ATTACKING THE FRUIT. 



297 



FIG. 308. 



About the middle of August some berries in the bunches 

 of grapes may be seen shrivelling up; on opening these, 

 many of them will be found to contain only one seed, and 

 that of an unusually large size; other larger berries will 

 contain two seeds, also swollen, most of the seeds having a 

 dark spot somewhere on their surface. On cutting open these 

 seeds, the kernel will be found almost entirely consumed, and 

 the cavity occupied by a small, milk-white, footless grub, 

 with a pair of brown, hooked jaws, a smooth and glossy skin, 

 with a few very fine, short, white hairs. 

 Fig. 308 shows this larva highly mag- 

 nified ; the small figure beneath indicates 

 its natural size. 



The larva changes to a pupa within 

 the seed during the spring months, and in July emerges as a 

 fly, escaping through a small, irregular hole. 



The fly so much resembles that shown in Fig. 309 (which 

 represents a closely-allied form belonging to the same genus) 

 that it is difficult to 

 distinguish between 

 the two ; a represents 

 the female, b the male, 

 c the antenna of the 

 female, d that of the 

 male, e the abdomen 

 of the female, showing 

 the segments or rings 

 of the body, /that of 

 the male. All these 

 figures are highly 

 magnified; the short 

 hair-lines underneath 

 the flies indicate the 

 natural size. The fly is black; the head and thorax are 

 finely punctated with minute dots ; the abdomen is long and 

 smooth, with a polished surface, and is placed on a sr )rt 



FIG. 309 



