CHAPTER XXV 



The Life History and Control of Fleas ^ 

 F. C. Bishopp 



The importance of flea control probably needs no further emphasis 

 than that already apparent after reading the lecture on the relation 

 of fleas to disease. It should be borne in mind that the plague has been 

 one of the most terrible scourges in the history of the world and that its 

 reduction to an inconspicuous place in Europe and the western hemisphere 

 has been the result of the knowledge of the relationship between rats and 

 fleas and Bacillus pestis, the causative organism of the disease. Aside 

 from the part which fleas play in the transmission of this dreaded malady 

 and certain other human ailments, they are often of decided importance 

 on account of the annoyance to man produced by their crawling about 

 over the body and biting. The susceptibility to attack of individuals 

 seems to vary greatly. In many cases a few fleas produce but little 

 annoyance and the bites leave no after efl^ect. In other instances the 

 crawling of the fleas produces much annoyance and the bites have been 

 known to form lesions of more or less serious character and often slow 

 to heal. 



To proceed intelligently with flea control it is important to have a 

 good general knowledge of their habits and distribution. Eleven species 

 of fleas have been shown capable of carrying plague. Eight of these 

 have been found to occur on one or more species of rat (^Epimys spp.) 

 and two on ground squirrels. Of these, the Indian rat flea undoubtedly 

 plays the principal role in the transmission of bubonic plague. The 

 following list includes most of the forms which may be considered 

 important to man either as vectors of disease organisms or as annoyers : 

 Pvlex irritans, Ctenocephalus cards, Ct. felis, Ceratophyll-ws fasciatus, C. 

 anisus, C. acutus, Xenopsylla cJieopis, X. scopvlifer, CtenophthaLmus 

 agyrtes, Dermatophilius penetrans, Echidnophaga gallmaceus, Hoplopsyl- 

 lus anoinalus. 



The host relations of fleas are very important, as has been seen by 

 considering the relationship of the insect to disease transmission. Unfor- 

 tunately most of the fleas are not very closely restricted to certain hosts, 

 especially when forced by hunger to seek blood. It might be stated at 



'This lecture was read November 4, 1918. 



360 



