SPECIES INJURIOUS TO WOOLEN GOODS, ETC. G5 



occasionally also injure woolens, but are not of sufficient importance to 



be here noted. 



The case-making clothes moth {Tinea pellionella Linn.; (fig. 2d is 

 the only species which constructs for its protection a true transport- 

 able case. It was characterized by Linnaeus and carefully studied by 

 Reaumur early in the last century. Its more interesting habits have 

 caused it to be often a subject of investigation, and its life history will 

 serve to illustrate the habits of all the clothes moths. 



The moth expands about half an inch, or from 10 to 11 mm. Its head 

 and fore wings are grayish yellow, with indistinct fuscous spots on the 

 middle of the wings. The hind wings are white or grayish and silky. 

 It is the common species in the North, being widely distributed and 

 very destructive. Its larva feeds on woolens, carpets, etc., and is espe- 

 cially destructive to furs and feathers. In the North it has but one 

 annual generation, the moths appearing from June to August, and, on 

 the authority of Professor Fernald, even in rooms kept uniformly 

 heated night and day it never occurs in the larval state in winter. In 

 the South, however, it appears from January to October, and has two 

 or even more broods annually. 



Pliny says of its larva that it --is clad in a jacket, gradually forming 

 for itself its own garment, like the snail in its shell, and when this is 

 taken from it, it immediately dies; but when its garment has reached its 

 proper dimensions it changes into a chrysalis, from which, at the proper 

 time, the moth issues. 77 



The larva is a dull white caterpillar, with the head and the upper 

 part of the next segment light brown, and is never seen free from its 

 movable case or jacket, the construction of which is its first task. If it 

 be necessary for it to change its position, the head and first segment are 

 thrust out of the case, leaving the thoracic legs free, with which it 

 crawls, dragging its case after it to any suitable situation. With the 

 growth of the larva it becomes necessary from time to time to enlarge 

 the case both in length and circumference, and this is accomplished in 

 a very interesting way. Without leaving its case the larva makes a 

 slit halfway down one side and inserts a triangular gore of new mate- 

 rial. A similar insertion is made on the opposite side, and the larva 

 reverses itself without leaving the case and makes corresponding slits 

 and additions in the other half. The case is lengthened by successive 

 additions to either end. Exteriorly the case appears to be a matted 

 mass of small particles of wool; interiorly it is lined with soft, whitish 

 silk. By transferring the larva from time to time to fabrics of different 

 colors the case maybe made to assume as varied a pattern as the 

 experimenter desires, and will illustrate, in its coloring, the peculiar 

 method of making the enlargements and additions described. 



On reaching full growth the larva attaches its case by silken threads 

 to the garment or other material upon which it has been feeding, or 

 sometimes carries it long distances. In one instance numbers of them 

 2805— No. 1 5 



