124 Psyche [August 



NOTES ON THE CAT FLEA (CTENOCEPHALUS FELIS 



BOUCHE).! 



By Harold Lyon. 



The following observations were made in connection with some 

 attempts during the past winter to devise a satisfactory method 

 for the propagation of fleas to be used for experimental purposes. 

 It had been intended to make use of the reared insects for exjjeri- 

 ments concerning their possible association with anterior polio- 

 myelitis (infantile paralysis), but as it was not possible to secure 

 proper facilities for this work at that time, it has seemed advisable 

 to publish earlier some of the observations. 



These relate primarily to the seasonal abundance of the cat 

 flea, since it is difficult to obtain from existing literature any ade- 

 quate data upon the relative abundance of fleas during the various 

 months of the year, in regions where there is a considerable annual 

 range of temperatures. The association between bubonic plague 

 and various fleas, particularly the tropical rat flea {Xenopsylla 

 cheopis) has long been known as well as the role of Ceratophyllus 

 Jasciotiis in transmitting plague in the more temperate regions of 

 the northern hemisphere. However, most of the work on plague 

 and fleas has been done in the tropics or subtropics and the careful 

 data collected in such climates cannot be applied to the conditions 

 which exist in our own region. Observations on the seasonal prev- 

 alance of Ceratophyllus fasciatus have been made notably in Eng- 

 land by Nuttall and also in California by Mitzmain, but none 

 seemed sufficient for the present purpose. It was therefore deter- 

 mined to make a uniform series of counts of the number of fleas 

 occurring on cats in the city of Boston from week to week during 

 as long a period as possible. With the kind permission of Mr. 

 Huntington Smith of the Animal Rescue League, it was possible 

 to examine the cats collected by the officers of the league and 

 these examinations have formed the basis for the accompanying 

 tabulations. The data on seasonal distribution begin with Decem- 

 ber 1914 and have continued to the present date of writing. 



1 Contributions from the Entomological Laboratory of the Bussey Institution, Harvard Uni- 

 versity, No 96. 



