248 THE STUDY OF INSECTS. 



granella, Adela ridingsella, Bucculatrix pomonella, and many 

 hundreds of others; until the syllable -ella always brings 

 before us a vision of a tiny moth, with narrow wings bear- 

 ing long delicate fringes. 



The Tineids are very numerous, there being nearly one 

 thousand described American species ; and doubtless there 

 are many undescribed as yet. The superfamily is composed 

 of several families; but, as the study of these insects is 

 too difficult to be carried far by the beginning student, we 

 will not take the space to define these families in this work. 

 We will merely describe the habits of a few species. 



At first thought the leaves of our common shrubs and 

 trees seem quite as thin as if they had been cut out of 

 sheets of paper. But the reader has doubtless learned in 

 the study of Botany that the upper and the lower surfaces 

 of a leaf are each covered with a thin skin or epidermis, and 

 that between these two skins there is a fleshy portion called 

 the parenchyma. But if botanists had failed to teach us 

 this lesson, the Tineid larvae would have done so ; for many 

 of these little creatures live until full grown between the two 

 skins of a leaf, and derive their nourishment from the paren- 

 chyma. As our coal-miners dig tunnels in the earth, so do 

 these larvae eat out long passages in the substance of a leaf, 

 without breaking through either epidermis. 



During the late summer and autumn there can be found 

 on almost any shrub or tree leaves that are more or less dis- 

 colored by white or grayish blotches or by long twisted 

 lines that reveal the abiding-places of leaf-miners. Surely 

 Mr. Lowell must have had these in mind when he wrote : 



" And there's never a leaf nor a blade too mean 

 To be some happy creature's palace." 



Not only are very many kinds of plants infested by 

 Tineid larvae, but the mines in the leaves differ greatly in 

 form and in their position in the leaf. These differences in 

 food-plant and in the shape and position of the mines do 



