HOUSE-FLY OR TYPHOID FLY 301 



Control. Frequent handling of the articles liable to attack is 

 the best remedy, for the "silver fish" does not like to be disturbed. 

 Naphthaline crystals scattered about where it may be present 

 form a good preventive. Housecleaning and treatment with gaso- 

 line is the best method against infestation. The insect may be 

 poisoned by soaking cardboard in thick flour paste in which Paris 

 green has been mixed, and placing pieces of the cardboard where 

 the insects are most abundant. 



Book Lice. These are wingless insects (Atropos sp., and 

 Clothilla sp.), almost colorless, very small, and barely evident to 

 the naked eye. They live upon vegetable matter and may be 

 frequently found in books or among starched linens which have 

 been laid away. Also they have been known to occur in great 

 numbers in mattresses stuffed with horse-hair or straw. 



Control. For infestation of mattresses, the only means of 

 control is by destroying the mattress or by fumigating it. Book 

 lice do not ordinarily occur in frequented places, especially if well 

 lighted and ventilated. Thorough scrubbing of woodwork and 

 furniture is desirable. Dust and brush infested bedding and cloth- 

 ing. Supplement the cleaning by applications of gasoline in cracks 

 and crevices not otherwise reached. 



The House-Fly or Typhoid Fly.- This common household pest 

 (Musca domestica Linn.), it should be noted, never bites. Its food 

 is always taken in a moist condition aud is first dissolved by the 

 fly; it rasps the surface with its tongue, pouring out upon it liquid 

 from glands or crop, or both, and after a solution of food is made 

 in this way it sucks it into its crop. This fly is often confused with 

 the stable-fly entering our houses in the late summer or autumn; 

 the latter is capable of stabbing the surface upon which it lies. 

 It must be noted, however, that there are several species of fly 

 resembling house-flies, but smaller. 



A Bad Pest. It is a most disgusting and injurious pest, known 

 to carry germs of typhoid fever, tuberculosis, cholera, dysentery, 

 and probably many other disease germs (Fig. 310). The typhoid 

 germ may live three weeks in the intestine of a fly, and fly-specks 

 are potential breeders of disease. It should be noted that this 

 insect is a conveyor of germs, and not an incubator or secondary 

 host. Germs are picked up in filth and carried to foodstuffs, 

 exposed groceries, and all accessible eatables. 



Life History. The house-fly, by preference, breeds in fresh 

 horse manure, but will lay its eggs in any form of filth: human 



