76 



NATURE STUDY AND LIFE 



of cracks a good way to trap them is to spread woolen 

 cloths on closet floors, taking them up daily and shaking 

 them over papers. The larvag, if kept in bottles and fed 

 on woolen cloth, may be observed to change into pupae 

 within their last larval skins. The pupa case finally is 

 split open on the back, and a little black beetle emerges. 

 It is about one-seventh of an inch in length and is cov- 

 ered with black, white, and brick-red scales, giving it a 

 mottled appearance. An amusing thing about the larvae 

 is that, if kept in a dry place without any food, they will 



Fig. 30. Carpet Beetle 



a, larva, dorsal view ; b, pupa within larval skin ; c, pupa, ventral view ; d, adult. 

 (All enlarged. After Riley) 



live for an almost indefinite time, feeding on their cast- 

 off skins, i.e., when one gets hungry he sheds his skin 

 and eats it. Great care should be taken to teach the 

 distinction between carpet beetles and our little lady-bird 

 beetles. These latter often come into our houses to pass 

 the winter and are killed by mistake. They are among 

 our best insect friends and may be worth a quarter apiece 

 for destroying plant lice, as we shall see when we come 

 to study insects of the garden. 



