THE HOUSE FLY 



343 



pays. For flies that gain entrance, a liberal use of fly 

 paper is recommended. If many flies have entered the 

 house, it is well to close it up, and disinfect with per- 

 manganate of potash and formalin. 



For a breeding place, the house fly prefers horse manure, 

 but it likes also any other manure. This is one more rea- 

 son (see Chapter IX) for removing barnyard manure to 

 the field as quickly as possible. Excretions in outhouses 



WORK OF THE SAN JOSE SCALE. 

 Note the many dead branches. 



should be covered with lime, ashes, land plaster, or plain 

 earth, to keep away the flies ; and, if any member of the 

 family has typhoid fever, the excretions should be treated 

 with formalin, or some other disinfectant. This treat- 

 ment should continue for a year after the disease has 

 disappeared. 



The power which flies have to reproduce is almost in- 

 credible, as is the case, too, with most other insects. 

 A fly lays about 120 eggs at a time. These eggs will 

 develop into adult flies in about ten days, and half of 



