126 LEAF-MINING INSECTS 



The mature larva is in general body characters typical of the 

 family. It is whitish, or, when it has fed up in the blotch mine, 

 greenish, without color markings. The abdominal feet bear seven 

 crochets in two curved rows all pointing backward. Length of 

 full grown larva, 6 to 7 mm. The entire larval period is about 

 twenty days. 



After it leaves its mine the larva lets itself down by a strand of 

 silk to a more secluded place where it spins a cocoon, nearly always 

 on the under side of a leaf near the edge or against one of the ribs. 

 The cocoon is a double affair consisting of a thin outer layer built 

 up from the leaf, and a second, similar, inner layer, everywhere 

 separated from the first by from 1 to 1.5 mm. The cocoon is 14 

 mm. long, white, rather flattened, oval and transparent. The 

 outer covering is decorated along the middle with from four to 

 ten small, pearl-like globules similar to those on the Marmara 

 cocoons, but fewer in number and less brilliant. 



Within its silken enclosure the pupa is plainly visible. 

 Throughout the pupal period it is noticeably active, revolving 

 rapidly on the axis of the body when disturbed; greenish brown 

 and structurally normal. The pupal period is six to ten days in 

 summer. 



The adult is a grayish-brown moth with a wing expanse of a 

 third of an inch (8 mm.) Its yellowish white palpi are ringed with 

 brown, and its grayish-brown fore wings are obliquely streaked 

 inward from both margins with white. 



In summer the entire life cycle of the insect from egg to imago, 

 is completed in a trifle over a month. 



Apophthisis 



A single species of this genus A. pullata, reared by Miss 

 Braun near Cincinnati, Ohio, and first described by her, 

 differs in having the mine at first deep in the tissue. The 

 mine, she says, lies deep in the leaf substance of buckthorn, 

 Rhamnus lanceolata Pursh. It is linear at first, gradually 

 broadening into an irregular blotch 5 or 6 mm. wide, occupy- 

 ing about one-fourth the area of the leaf. The leaf retains 

 its green color so that the mine is not clearly visible during 



