268 THE STUDY OF INSECTS. 



spines along the back, and other shorter ones upon the sides. 

 When not eating, the larvae remain close together, some- 

 times completely covering the branch upon which they rest. 

 This species passes the winter in the pupa state. The adults 

 appear in June and July. 



The Mocha-stone Moths, IcJitliynra (Ich-thy-u'ra). — To 

 the genus Iclithyura belong several species of brownish-gray 

 moths, whose fore wings are crossed by irregular whitish 

 lines. It was these peculiar markings, resembling somewhat 

 those of a moss-agate, that suggested the popular name 

 given above. The larvae feed on poplar and willow, and 

 conceal themselves within nests made by fastening leaves 

 together. Our most common species is the following: — 



The Poplar Mocha-stone Moth, IcJitliynra incliisa (I. in- 

 clu'sa). — The adult (Fig. 318) is a brownish-gray moth, with 



the fore wings crossed by three irregu- 

 lar whitish lines. The basal line is 

 broken near the middle of the wing; 

 and the intermediate one forms an in> 

 verted Y, the main stem of which joins 

 Fig. y&.-ichthyura inciusa. the third line near the inner margin of 

 the wing, making with it a prominent V. These lines are 

 bordered without by rust-red ; there is a chocolate-colored 

 spot near the apex of the fore wings, and an irregular row 

 of blackish dots near the outer margin. The hairs of the 

 thorax form a prominent crest, the fore side of which is a 

 rich dark brown. The hind wings are crossed by a wavy 

 band, which is light without and dark within. 



The eggs are nearly spherical and smooth ; they are 

 deposited in a cluster a single layer deep on a leaf (Fig. 

 319). When the larvae hatch they make a nest either by 

 fastening several leaves together or, as is the case when 

 they infest poplar, by folding the two halves of a single leal 

 together; frequently in the latter case the tip of the leaf is 

 folded in as shown in the figure. Within this nest the entire 

 colony lives, feeding on the parenchyma, and causing the 



