LEP1D OP TERA . 257 



Other Case-bearers. — The two case-bearers described 

 above make their cases out of fragments of leaves ; there 

 are others that use the husks of seeds which they have 

 eaten. Such cases are extremely protective, appearing to 

 be merely seeds. But there are some Tineid case-bearers 

 that make their cases entirely of silk. These are usually 

 more or less nearly cylindrical, and are carried projecting 

 out at a considerable angle from the object upon which the 

 insect walks. When the insect is at rest and when it is 

 undercoin^ its transformations the mouth of the case is 

 closely fastened to some object, so that the insect is com- 

 pletely concealed. Considerable differences exist in the 

 form of these silken cases. In a quite common type the 

 case is nearly cylindrical, with a flaring lip at the head end, 

 and with the hind end three-sided, as if it had been pinched 

 between one's thumb and two fingers. In another type the 

 hind end of the case is somewhat enlarged and curved down- 

 ward so that the case is shaped like a pistol. 



The Clothes-moths. — These are the dread of every house- 

 keeper. The mere mention of the word "moths" is enough 

 to conjure up visions of household treasures of woolen and fur 

 eaten full of holes, their beauty gone, their usefulness past. 

 It was formerly supposed that these well-known injuries 

 were caused by a single species ; but it has since been dis- 

 covered that we have in this country three species of clothes- 

 moths. These differ in habits as well as in structure. 



The Case-bearing Clothes-moth, Tinea pellionella (Tin'e-a 

 pel-li-o-nel'la). — The larva of this species is a true case- 

 bearer, making a case out of bits of its food-material which 

 are fastened together with silk. As the larva grows it en- 

 larges its case by adding to each end and by slitting it and 

 inserting a piece. Instructive specimens can be obtained by 

 rearing the larvae, and changing them from time to time 

 from flannel of one color to that of another. The shape of 

 the successive additions to the case, being of different colors. 

 can be easily seen. The pupa state is passed within the 

 18 



