SOME TROUBLESOME INVADERS 379 



tails demand certain degrees of moisture and cannot 

 survive in dry situations such as are ordinarily found 

 in most parts of a house. 



In situations like the milk-house to which reference 

 was made in the letter quoted, we would suggest that 

 everything portable should be removed from the room, 

 and the earth floor, walls, and shelves swept as clean as 

 possible. Then a liberal application of dry, slaked lime 

 should be applied to the floor, woodwork, and as much as 

 possible to the walls. It would probably be helpful to 

 add sulfur to the lime in almost any proportions desired. 



When these insects become troublesome in the house- 

 hold proper, the moist objects or surfaces on which they 

 gather should be removed, if possible. If it is not feasible 

 to remove the moist objects, they could be dried by the 

 application of slaked lime and sulfur, or in any other 

 manner that may suggest itself as most convenient. 



THE BOOK-LOUSE 



Atropos divinatoria 



Often, when an old book or paper yellowed with age 

 that has lain long unhandled on the shelves is removed 

 and the leaves turned, numerous, pale-colored, wingless, 

 lice-like insects may be seen scudding across the pages and 

 scurrying away to hide themselves in a crack or crevice. 

 They are commonly known as book-lice and are so small 

 that nothing can readily be made out about them unless 

 a hand lens or magnifying glass is used. In fact, they are 

 among the smallest of the insects and belong to the family 

 Psocidce, a group of insects probably most closely related 



