154 LEAF-MINING INSECTS 



The sour gum case-cutter, A. nyssaefoliella, first makes 

 linear mines which end in a blotch that often is widened so 

 as to obliterate the earlier portion. It is widely distributed 

 and very often destructive in the eastern United States. 



Coptodisca 



In this genus the mines are wont to begin as very narrow 

 lines, afterwards expanding to a small transparent blotch. 



Fig. 47 Fig. 48 



Fig. 47. A leaf of wild grape bearing a mine of Antispila [viticordifoliella. 

 Fig. 48. A leaf of sour gum bearing mines and excisions'of Antispila 

 nyssaefoliella. 



The whole mine indeed is very small. Frequently there are 

 many mines in one leaf. Busck has reported 30 to 40 mines 

 in a single leaf for C. arbutiella and Comstock figures more 

 than thirty mines of C. splendoriferella in a single apple 

 leaf. While the cases of Antispila are usually cut from the 

 very edge of its large blotch mines, the'cases of Coptodisca 



