182 



MOTHS. BOMBYCID.E. 



FIG. 508. CATERPILLAR, LEAF-COCOON, AND CHRYSALIS 

 OF THE PROMETHEUS MOTH 



American species, which, previously to spinning, draws together 



the sides of a leaf (within which it afterwards forms its cocoon), 



and fastens its stalk 

 to the stem by a 

 strong silken web 

 (Fig. 508). The 

 genus Bombyx is 

 one of great in- 

 terest and import- 

 ance, as containing 

 the Bombyx mori, 

 whose larva fur- 

 nishes all our silk. 

 Of the numerous 

 other species of the 

 family, some much 

 resemble a bundle 

 of dead leaves, both 



in colour and form, when their wings are closed ; such is the 



Gastropacha quercifolia, or Oak-leaf Moth (Fig. 509). The 



Caterpillars of other species are re- 

 markable for their curious habits. 



They live in societies on the leaves 



of the oak ; and spin, when young, 



a kind of silken tent, divided 



within into cells. They may be seen 



to issue from it in the evening in a 



procession, one of them, which 



seems to act as a guide, advancing 



at the head, two then following, 



then three, then four, and so on, 



each rank containing one more than 



the preceding one. Hence they have 



been called processionary caterpillars. 



Each spins a separate cocoon ; but 



they are united in regular apposition, 



being laid side by side against each other. 



777. The family NOCTUID^J contains a great proportion of 



FIG. 509. GASTROPACHA QVER- 



ClFOLlA. 



