United States. Pulex irritans is sometimes found in houses in 

 California, and is the prevailinjr household flea of Europe. A house 

 may become infested with the cat and dog flea even though no 

 domestic animals be kept, for a visitor at a house Avhere such pets 

 are maintained may be the means of carrying home with him one or 

 two female fleas which will stock his own premises. Of course, where 

 a pet dog or cat is kept, the source of the infestation is manifest. 



The worst cases of infestation reported to this Bureau have usually 

 been those in which houses had been temporarily unoccupied during 

 the summer. Such houses during a rainy summer become more or 

 less damp, and as a rule the customary sweeping of the floors is inter- 

 rupted, thus furnishing the very conditions under M-hich, as we shall 

 see, fleas most readily propagate. 



The eggs (fig. 1, a) of Ctcnocephalus canis are deposited among the 

 hairs of cats and dogs, but as they are not attached to the hairs, 

 numbers drop off whenever the infested animal moves or lies down. 

 From these eggs hatch the larva' (fig. 2, «), which are slender, 

 minute, white, wormlike creatures. They are very active, crawl rapidly, 

 penetrate into the cracks of the floor, and live there until full grown, 

 feeding upon such organic matter as may have collected in the 

 cracks. They develop rapidly, and in midsummer in Washington 

 reach full growth in a short time. On reaching full growth the 

 larva spins a delicate, white, silken cocoon (fig. 1, &), and transforms 

 to pupa (fig. 1, c), the adults (fig. 1, d) issuing a few days later. 

 A whole generation may develop in the course of a fortnight in warm, 

 damp weather, but a great excess of moisture results in the destruc- 

 tion of the larva}. With this rapid development under the most 

 favorable conditions, a housekeeper, shutting up her house in June,, 

 for example, with a colony of fleas too small to be noticed inside the 

 house, should not be surprised to find the establishment overrun with 

 fleas when she opens it again in September or October. 



REMEDIES. 



If you do not desire to be troubled by fleas, do not keep cats or dogs. 

 If you must keep a pet dog or cat, provide a rug for the animal to 

 sleep on, and give this rug a frequent shaking and brushing, after- 

 wards sweeping up and burning the dust thus removed. As all the 

 flea eggs on an infested animal will not, however, drop off in this way, 

 and as those which remain on it Avill probably develop successfully, 

 it will be found wise to occasionally rub into the hair of the dog or 

 cat a quantity of pyrethrum powder. If thoroughly applied, this 

 powder Avill cause the fleas to fall oft' in a half stupefied condition, 

 when they, too, may be SAvept up and burned. 



The larvae of the dog and cat flea will not develoj) successfully in 

 situations where they are likely to be disturbed. The use of carpets 



[Cir. 108] 



