364 SANITARY EXTO:\IOLOGY 



cat family. They arc occasionally found on rats. They are quite widely 

 distributed throughout the temperate and tropical j)arts of the world. 

 In the United States they often occur as household pests, and in the 

 Central and Eastern States they usually take the place of the human flea 

 as parasites of man, most of the outbreaks in these regions being from 

 either one or the other of these species. 



The European rat flea Cerafophyllus fasciatus Bosc is rather 

 closely restricted to the several species of rats and mice but it has been 

 found to bite man in the absence of its preferred hosts and probably 

 also will feed on other animals. It is the predominant rat flea in tlip 

 United States and over the greater part of Europe, and in this region 

 must be considered one of the principal vectors of plague. In the tropics 

 it is much less abundant, occurring only in the cool season. 



Fig. 68. — The European rat flea, Ci'mtophjillns fasciatus: Adult female. Greatly 



enlarged. (Bishopp.) 



The Tropical or Indian rat flea (Xenopsylla cheopis Roth.) is 

 undoubtedly the principal disseminator of bubonic plague in India and 

 other parts of Asia. It is also now to be found in practically all the 

 other tropical and subtropical countries of the world, but it is often 

 restricted to the seaport towns, as in the case of the United States, where 

 it appears not to have penetrated far inland. This species is primarily a 

 rat flea, being taken on all species of rats and mice, but it feeds readily 

 upon man and also will attack small domestic animals and .some wild ones. 



The mouse flea {Ctenopsylla musculi Duges) is to be found in many 

 parts of the world but is especially abundant in Mediterranean Europe, 

 Australia, and the southern part of the United States. It is often found 

 in numbers on rats as well as mice, but rarely bites man even in the 

 absence of its preferred hosts. 



The Asiatic rate flea (CeratoplujUus anisus Roth.) appears to take 

 the place to a largo extent of the European rat flea, in Japan and portions 

 of northeastern China. A species of groundhog flea (Ceratophyllus 



