334 



AN INTRODUCTION TO ENTOMOLOGY 



Atropos pulsatdria. — In this species the fore wings are represented 

 by small convex scales; it is of a pale yellowish white color and is a 

 little more than i mm. in length. 



Each of these species has been known as the death-watch, as they 

 have been believed by superstitious people to make a 

 ticking sound that presaged the death of some person 

 in the house where it is heard. It is not probable that 

 such minute and soft insects can produce sounds 

 audible to human ears. The sounds heard were prob- 

 ably made by some wood-boring beetles, Anohiids, 

 which are also known as the death-watch. 



Book-lice are found chiefly in damp, well-shaded 

 rooms, not in general use. They do not attack man, 

 but feed upon dead vegetable and animal matter, as 

 the paste in book-bindings, wall-paper, and photo- 

 graphs. They rarely occur in sufficient numbers to 

 do serious injury. They can be destroyed by fumigating the infected 

 room with hydrocyanic acid gas. This, however, should be used only 

 by experienced persons. Ordinarily a prolonged heating and drying 

 of the room will be sufficient to destroy them. 



Fig. 381. — A 

 book-louse. 



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