HOUSEHOLD AND CAMP INSECTS 35 



The deadly bubonic plague is carried by a number of fleas, 

 notably the Indian rat flea, the European rat flea, 77 the human flea, 78 

 the European mouse flea, 79 the dog flea, 80 the squirrel flea, 81 the cat 

 flea, 82 and the rat fleas. 83 This is of grave importance, since the 

 Indian rat flea is abundant in parts of the seaport cities of the 

 Pacific and Gulf coasts of the United States, while away from the 

 waterfront its place as a rat parasite is largely taken by the 

 European rat flea and the mouse flea. A recent study of rat fleas 

 at Providence, R. I., showed that the Indian rat flea comprised 75 

 per cent, the European rat flea 22 per cent, the European mouse 

 flea 2.5 per cent, and the dog flea .5 per cent on a total of 341 rats 

 examined. The average between July and September was 10.2 

 fleas to a rat, and from October to December 3-7. 84 Consequently 

 it is only necessary to introduce an infected rat in any of these 

 localities to make possible an outbreak of this deadly plague, some- 

 thing which may easily result under present disturbed trade and 

 traffic conditions. Indian rat fleas are not very active and indi- 

 viduals from plague-stricken rats are likely to reach only human 

 beings living in the same house. 85 This species is able to transmit 

 plague 33 days after feeding upon an infected animal. The 

 European rat flea is able to carry plague bacilli for periods of 

 from 2 to 47 days in the absence of the host. 80 British troops at 

 Hongkong provided only with boots were much bitten by fleas and 

 many contracted plague; while others in India equipped with 

 " putties " did not contract disease because fleas could not get at 

 their ankles. 87 



The European hen flea 88 has been recorded from both New 

 York and Massachusetts, while the so-called " sticktight " flea 89 is 

 an important and common pest of poultry in the southern and 



77 Ceratophyllus fasciatus Bosc. 

 78 Pulex irritans Linn. 

 79 Leptopsylla musculi Duges. 

 80 Ctenocephalus canis Curtis. 



81 Hoplopsyllus anomalus Baker and Ceratophyllus 

 a c u t u s Baker. 



82 Ctenocephalus felis Bouche. 



83 Ceratophyllus anisus Roth, and Pygiopsylla ahalae 

 Roth. 



84 Robinson. Amer. Jour. Pub. Health, p. 773-76. 1913. 



85 Schwellingrebel. Centralbl. Bakt. Parasit. Infektions, 74:456-66; 592- 

 693. 1915. 



80 Bacot Jour. Hyg., Cambridge. Plague Sup., 4:770-73. 1915. 



87 Gossard. Jour. Econ. Ent.. 2 :32O. 1909. 



88 Ceratophyllus gallinae Schrk. 

 89 Echidnophaga gallinacea Westw. 



