LEPIDOPTERA 



Fig. 348. — Wings of Tkyridopleryx ep/iemertrformis. 



In the adult state the two sexes differ greatly. The female is wingless, 

 and in some genera the eyes, antennae, mouth-parts, and legs are vestigial 

 or wanting, the body being quite maggot-like. At the caudal end of the 

 body there is a tuft of hair-like scales which are mixed with the eggs. 

 In most species the female does 

 not leave the sac before oviposition 

 but deposits her eggs within it. 



The male moths are winged; 

 they are small or of moderate size. 

 The wings are thinly scaled and 

 in some species nearly naked ; when 

 clothed with scales they are usually 

 of a smoky color without mark- 

 ings. The venation of the wings 

 varies greatly within the family. 

 Figure 3 48 represents the venation 

 of our most common species. 



Only about twenty species are 

 known from our fauna, of which 

 the following are most likely to be 

 observed. 



Abbot's bag- worm, Oiketicus 

 abboti. — This species occurs in the 

 more southern part of our country. 

 The larva makes a bag with sticks 

 attached to it crosswise (Fig. 347). The adult male is sable brown, with a 

 vitreous bar at the extremity of the discal cell of the fore wings; the 

 narrow external edging of the wings is pale; the expanse of the wings is 

 1 1 inches. 



The evergreen bag- worm, Thyridopteryx ephemera for mis . — This 

 species prefers red cedar and arbor-vita?, and for this reason has been 

 named the evergreen bag-worm; but it also feeds on many other kinds 

 of trees, and as it is the species that is most likely to attract attention, 

 and is sometimes a serious pest, it is often called the bag-worm. It is 

 our best-known species, and its life-history will serve as an illustration of 

 the habits of the members of the family Psychidae. 



The bag of this species is about the same size as that of Abbot's 

 bag-worm (Fig. 347) ; but differs in being covered with sprays of leaves 

 when it feeds on cedar or arbor-vitse, or with twigs attached lengthwise 

 when it feeds on other trees. When full-grown the larva fastens the bag 

 to a twig with a band of silk, and then changes to 

 a pupa. When the male is ready to emerge, the pupa 

 works its way to the lower end of the bag and half- 

 way out of the opening at the extremity. Then its 

 skin bursts and the adult emerges. The male moth 

 has a black, hairy body and nearly naked wings (Fig. 

 349). The adult female only partly emerges from the 

 pupa skin and awaits the approach of the male. She 

 is entirely destitute of wings and legs. The abdomen of the male can be 

 greatly extended, making possible the pairing while the female is still in the 

 bag. After pairing, the female works her way back into the pupa skin, where 

 she deposits her eggs mixed with the hair-like scales from the end of her 



Fig. 340- 

 leryx ephemerajormis. 



