94 



INSECTS AND HUMAN WELFARE 



culent, bristly grubs (Fig. 41), very resistent to extreme dry- 

 ness and otherwise very tenacious of life. Their origin and 

 habits are somewhat shrouded in mystery ; at least one of our 

 species is of European origin and the other is probably a 

 native American insect. Their depredations have been j artic- 

 ularly noted in households of only certain of our cities and as 

 the adult beetles are often abundant upon flowers far from 

 dwellings, the larvae undoubtedly breed generally in the open. 



FIG. 41. Larvse of the carpet beetle. These bristly little insects devour furs, woolens, and 

 all sorts of materials of animal origin, even the dried bodies of insects of other kinds. On 

 account of this last habit, the entomologist frequently finds them feasting upon his mounted 

 specimens. 



The beetles commonly appear on window panes in the spring 

 in company with the somewhat larger, brown Attagenus pi- 

 ceus, a related widespread insect of similar habits. 



One of our most generalized and primitive wingless insects, 

 known as Lepisma is a common household insect. It is a long 

 tapering, scaly insect with three slender thread-like append- 

 ages at the tip of the body, rather suggestive of a fish on 

 account of its form and glistening coat and hence commonly 

 called the : ' silver-fish." The silver-fish feeds upon glue, 

 paste or starch and will gnaw into wall-paper, starched 

 clothing or even bookbindings to feed. It studiously avoids 



