LEPIDOPTERA. 



249 



not indicate that these larvae are inconstant in their habits. 

 In fact, the opposite is the case. Each species of Tineid 

 infests a particular 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 Tineid that made a mine by 

 merely examining the infested leaf. 



The various kinds of mines can be classed under a few 

 distinct types. The long, narrow, and more or less winding 

 mines are described as 

 linear mines. Some of 

 these are very narrow at 

 their beginning and grad- 

 ually enlarge, resembling 

 in outline a serpent ; fre- 

 quently the larger end is 

 terminated by a blotch- 

 like enlargement, suggest- 

 ing a head. Such mines 

 are termed serpentine 

 mines. The leaves of the 

 wild columbine are often 

 marked by serpentine 

 mines (Fig. 297). Other 



mines that start from a narrow beginning enlarge more 

 rapidly and extend in a more or less regular curve ; these 

 are trumpet mines, A common example of a trumpet 

 mine is that made by the larva of Tischeria malifoliella 

 (Tis-che'ri-a mal-i-fol-i-el'la) in the leaves of apple. The 

 mines of many species are mere disk-like blotches ; these are 

 referred to as blotch mines (Fig. 298). Blotch mines differ in 

 position ; some are immediately beneath the upper epider- 

 mis, while others are nearer the lower surface of the leaf. 

 This distinction exists also in most of the other types of 



Fig. 297.— Leaf with serpentine mines. 



