SUPERFAMILY TINEOIDEA 



141 



tious matter is smeared in a waxy layer irregularly over the 

 floor of the mine, making it brown and dirty except at the 

 borders where it is fairly clean. 



The pupa of the summer brood is formed beneath a flat 

 circular sheet of silk attached at its edges to the lower side 

 of the leaf. The over-wintering larvae prepare the typical 

 hemispherical hibernating chambers described above. 



Fig. 45. A brown blotch mine of the witch hazel as seen in autumn, 

 containing three hibernating cocoons. 



COLEOPHORIDAE 



The case-bearers 



This family is represented in North America by a single 

 large genus, Coleophora, containing a hundred or more 

 species, many of which begin life as leaf-miners. Many of 

 them are external feeders, and of these that mine, none dwell 

 within their mines longer than the first instar. All con- 

 struct portable cases, which they carry on their backs. If 

 they do any mining after constructing cases, they do it as 



