250 THE INFANCY OF ANIMALS 



this is the case with the strange carnivorous caterpillar, 

 Erastria scitula of Southern Europe. This is the larval 

 form of a Noctuid moth which lays its eggs singly, and far 

 apart, on trees infested with scale insects. When hatched 

 the young caterpillar selects a large female coccid, and, 

 eating its way through the scale, devours the insect be- 

 neath, passing on to find a fresh victim. As it proceeds it 

 fashions a coat for itself of the scaly jackets of its victims 

 and its own excrement, binding the whole together with 

 silken threads. Covered by this extraordinary garment, 

 it resembles the bark of the tree, enabling it to roam 

 about from place to place without fear of detection ! 



Wonderful as these cases and coverings undoubtedly are, 

 none of those so far surveyed have any claim to be re- 

 garded as beautiful. But this is not so with the strange 

 silken and basket-work houses fashioned by the cater- 

 pillars of the moths of the family Psychidae. Those of the 

 genus Apterona weave a silken case indistinguishable, save 

 to the touch, from a small snail-shell. So faithful is the 

 model that the first specimens received by the British 

 Museum were sent as shells ! Others build similar shells 

 of earth, and aU these, it should be noted, live among grass 

 where real snails of this shape abound. Some build ex- 

 quisite spirally shaped baskets with pieces of wood all 

 cut to the same length, as in our illustration. When at 

 rest they suspend the basket by silken threads, and these 

 are cut away when the tiny householder desires to move 

 about in search of food. A similar device, as everybody 

 knows, is practised by the caddis-worm ; but it is more 

 than remarkable to find such widely different creatures 

 adopting the same device in their larval stages. 



Mention was made just now of a caterpillar which 

 built itself a covering made of the skins of its victim, and 



