354 PESTS OF THE HOUSEHOLD AND STORED PRODUCTS 



the other water. Use four parts of flour to one part of plaster of 

 Paris. Arrange the dishes so that roaches can easily climb on them and 

 pass from one to the other. Badly infested buildings may be entirely 

 cleared by fumigation with hydrocyanic acid gas. Great care should 

 be taken in using this treatment, for it is violently poisonous. 



Fleas 



Fleas are too well known to need description. Where houses become 

 infested, the trouble is nearly always traceable to a pet cat or dog, 

 although the pest may be brought in on clothing of a visitor. The 

 species usually observed is the common Cat 

 and Dog Flea (Ctenocephalus canis Curt.). 

 ^^H^^^ The adult flea lays eggs among the hairs of 



J^^^H9^ its animal host. These drop off, and the egg 



ST yE' ^ hatches to form a minute, white, slender larva, 



Vv \^ which lives in cracks in the floor or other pro- 



tected places, feeding on any available organic 



matter, such as hairs, or even dust. The 

 Fig. 557. — The Cat and , , <• , i i j^ j^i i tj 



Dog Flea Enlarged ^^^^^ transforms to a pupa, and later the adult 



and natural size. Orig- emerges, ready to leap on the first cat or dog 



i^^l- that comes its way, or on a human being. 



To rid a house of fleas all cracks must be washed with hot suds, and 

 preferably dosed with gasoline. At the same time any animal pets 

 must be looked after and cleared of the insect. Insect powder dusted 

 thoroughly into the animal's fur will stupefy the fleas and cause them 

 to drop off. They may then be gathered up and destroyed. 



Another treatment is to scatter over the floor of a room 4 or 5 pounds 

 of naphthaline, and keep the place tightly closed for 24 hours. This 

 will effectually^ rid a room of the adult insects, but will not be likely to 

 affect any eggs that might be present. The naphthaline may be swept 

 up and used over again. 



The Bedbug (Cimex lectularius Linn.) 



The bedbug is an ancient and cosmopolitan insect, existing through- 

 out the world. It has become wholly domesticated, and lives entirely 



