280 



THE INSECT WORLD. 



which is a sort of tissue of wool, sometimes blue, sometimes green, 

 sometimes red, according to the colour of the stuff to which the 

 insect attaches itself and which it despoils. The exterior of this 

 sheath is, on the contrary, formed of silk made 

 by the insect itself, of a whitish colour. 



The caterpillars are hardly hatched before 

 they begin to clothe themselves. Reaumur ob- 

 served one of these worms during the operation 

 of enlarging its case. To do this it put its head 

 out of one of the extremities of its sheath, and 

 looked about eagerly, to the right and to the 

 left, for those bits of wool which suited it best for weaving in. In 

 Fig. 294, we see two larvae occupied in eating a piece of cloth. 



Fig. 293. 



The Woollen Moth 

 (Tinea tapezella). 



Fig. 294. Larvae of the Woollen Moth ( Tinea tapezella). 



" The larva changes its place continually and very quickly," says 

 Reaumur. " If the threads of wool which are near it are not such as 

 it desires, it draws sometimes more than half its body out of its case 

 to go and look for better ones farther off. If it finds a bit that pleases, 

 the head remains fixed for an instant ; it then seizes the thread with 

 the two mandibles which are below its head, tears the bit out after 

 redoubled efforts, and immediately carries it to the end of the tube 

 against which it attaches it. It repeats many times in succession a 

 similar manoeuvre, sometimes coming partly out of its tube, and then 

 again re-entering it to fix against one of its sides a new piece of wool." 



