200 



THE STUDY OF INSECTS 



venation of the wings is quite generalized (Fig. 346), the base of media 

 being preserved in both fore and hind wings and all of the veins charac- 

 teristic of the Frenatac being 

 present ; but in other genera 

 the venation is somewhat re- 

 duced. 



Many of the larvae are 

 case-bearers ; many are scav- 

 engers or feed on fungi ; some 

 feed on fabrics, especially 

 those that contain much 

 wool; few if any feed on 

 leaves. 



This is a large family. 

 More than one hundred 

 twenty-five North American 

 species are already known; 

 fifty of these belong to the 



Fig. 346. — Wings of Tinea parasilella. (After Spuler.) 



genus Tinea. To this family belong the well-known clothes-moths. 



The naked clothes-moth, Tineola biselliclla. — This is our most com- 

 mon clothes-moth. Although the larva spins some silk wherever it goes, it 

 does not make a portable case; it is, therefore, named the naked clothes- 

 moth. But when the larva is full-grown it makes a cocoon, which is 

 composed of fragments of its food-material fastened together with silk. 

 The adult is a tiny moth with a wing-expanse of from ^ to § inches; it 

 is of a delicate straw-color, without dark spots on its wings. 



The case-bearing clothes-moth, Tinea pellionella. — The larva of this 

 species is a true case-bearer, making a case out of bits of its food-material 

 fastened together with silk. The case is a nearly cylindrical tube open 

 at both ends. The pupa state is passed within the case. The adult is a 

 small, silky, brown moth, with three dark spots on each fore wing. It 

 expands about \ of an inch. 



The tube-building clothes-moth or the tapestry-moth, Trichophaga 

 tapetiella. — The larva of this species makes a gallery composed of silk 

 mixed with fragments of cloth. This gallery is long and 

 winding and can be easily distinguished from the case of 

 the preceding species. The pupa state is passed within 

 the gallery. The moth differs greatly in appearance from ^M 



the other two species, the fore wings being black from 

 the base to near the middle, and white beyond. It 

 expands from \ an inch to one inch. 



Family Psychid^e 



The Bag-worm Moths 



The bag-worm moths are so called on account of the 

 silken sacs made by the larvae, in which they live and in 

 which they change to pupae. In our more conspicuous 

 and best-known species the sac is covered either with 

 little twigs (Fig. 347) or, in the case of a species that 

 feeds on cedar or arbor-vitae, with bits of leaves of these plants. When the 

 larva is full-grown it fastens its sac to a twig and transforms within it. 



Fig. 347. — Bag of 

 Oiketicus abboti. 



