208 INSECT LIFE. 



THE LEAF-MINERS. 



There are many leaf-eating caterpillars that are so 

 minute that they can live within the substance of a 

 leaf, the space between the two skins of the leaf being 

 sufficiently large to afford them room for a dwelling 

 and pasture. The larvae that live in this way are 

 called leaf-miners. 



During the late summer and autumn there can be 

 found on almost any shrub or tree leaves that are 

 more or less discolored 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 blade nor a leaf too mean 

 To be some happy creature's palace. 



Not only are very many kinds of plants infested 

 by these 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 not indicate that these larvae 

 are inconstant in their habits. In fact, the opposite 

 is the case. Each species of leaf-miner infests a par- 

 ticular species of plant, or, at the most, several closely 

 allied plants. And each species makes a mine of 

 definite shape, although some species exhibit different 

 habits in the different stages of their growth. So 

 constant are these creatures in their habits that in 

 most cases an expert can determine the species of 

 leaf-miner that made a mine by merely examining 

 the infested leaf. 



The various kinds of mines can be classed under a 



