SUPERFAMILY TINEOIDEA 133 



the cell-shearing type they separate the epidermis of the 

 lower side of the leaves. Then they spin silk to cause the 

 epidermis to become wrinkled, and feed afterward upon the 

 parenchyma of the arched side of the mine. They all live 

 in the leaves of herbaceous composites. 



In preparing for pupation the larvae of this division spin 

 elongate white cocoons smooth or ridged from end to end. 

 These are suspended in the mine in a very characteristic 

 hammock-like way by two slightly diverging silken threads 

 at the posterior end and one or two threads at the anterior 

 end. The pupae penetrate through these cocoons and 

 through the leaf tissues just before the adults are freed. 



The goldenrod leaf-miner, C. solidaginis, is one of the 

 commoner species in the United States. It mines the under- 

 side of the leaves of species of goldenrod, making elongate 

 much wrinkled mines. The cocoons spun by this species 

 are dense and white marked with longitudinal ridges. They 

 are suspended in the mine by a single silken thread at the 

 anterior end and by two diverging threads at the posterior 

 end. 



Lithocolletis* 



This is the greatest genus of leaf-miners in the world. 

 Some 200 species have been described from North America 

 alone, and, doubtless, there are others still unknown. They 

 probably outnumber all remaining leaf-mining Lepidoptera 

 together. The world is full of them. If any one would 

 find them for himself he has only to search for a few moments 

 the green leaves of such trees as oaks, witch hazel, lindens 

 and birches. Our lists will show (p. 317) that they have a 

 marked predilation for oaks, hornbeam and nut-bearing 

 trees, and that few of them infest herbaceous plants. Both 

 larval and pupal stages are passed within the mine. Dur- 

 ing the first three instars the larvae are of the flat, sap-feed- 



3 Called also Phyllonorycter . 



