BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 1/9 



cockroaches. In seven of the experiments cysts of E. coli were found 

 in the feces. Cysts were observed in the feces for only one to three 

 days, and eventually disappeared completely. The cysts appeared to 

 be unharmed. No amoebae were found. 



♦ Entamoeba histolytica Schaudinn 



Natural vectors. — Blatta orientalis, Blattella germanica, Periplaneta 

 americana, Periplaneta australasiae , and/or Sitpella supellectilium, 

 Peru (Schneider and Shields, 1947). 



Blattella germanica and/or Periplaneta americana, Egypt (De- 

 Coursey and Otto, 1956, 1957). 



Cockroaches, Venezuela (Tejera, 1926). 



Experimental vectors. — Blatta orientalis, Italian Somaliland (Mari- 

 ani and Besta, 1936). 



Periplaneta americana. Gold Coast Colony (Macfie, 1922) ; U.S.A. 

 (Frye and Meleney, 1936). 



Cockroaches, Venezuela (Tejera, 1926). 



Entamoeba pitheci Prowazek? 



Experimental vector. — Periplaneta americana, Formosa (Mori- 

 schita and Tsuchimochi, 1926) : Eleven of 15 cockroaches fed feces of 

 a monkey [Macaca cyclopis (Swinhoe)] containing cysts of the 

 amoeba voided live cysts in their own feces. 



Entamoeba thomsoni Lucas 



Synonymy. — Endamoeba thomsoni [Kudo, personal communica- 

 tion, 1957]. 



Natural hosts. — Blatta orientalis, England (Lucas, 1927a, 1928) ; 

 U.S.A. (Taliaferro, 1928; McAdow, 1931); U.S.S.R. (Zasukhin, 

 1930); Germany (Chen, 1933). 



Blattella germanica, U.S.A. (McAdow, 1931). 



Periplaneta americana, England (Lucas, 1927a) ; U.S.A. (Smith 

 and Barret, 1928; McAdow, 1931) ; Philippine Islands (Hegner and 

 Chu, 1930). 



The organism is found in the hind intestine and rectum of the cock- 

 roach. Smith and Barret (1928) developed a synthetic medium in 

 which cultures of E. thomsoni were carried through successive trans- 

 fers for 24 months. 



Entamoeba sp. 



Natural vector. — Periplaneta americana. Gold Coast Colony (Mac- 

 fie, 1922) : Under the heading "Entamoeba histolytica and E. coli" 



