BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS I3I 



Aspergillus sp. 



Natural vector. — Periplaneta americana, England (Bunting, 1956) : 

 The fungus was isolated mostly from imperfectly excreted feces. 



Beauveria bassiana (Balsamo) Vuillemin 



Experimental host. — Blattella germanica and Periplaneta americana, 

 U.S.A. (Dresner, 1949, 1950) : The nymphs of American cockroaches 

 became infected when they (i) were injected with a i -percent suspen- 

 sion of spores, (2) ate rat pellets sprayed with the spore suspension, 

 or (3) were dusted with the fungus spores. The symptoms of the 

 fungus infection were paralysis followed by death ; some of the 

 infected insects liquefied, others dried up after the appearance of a 

 subcuticular blackening. 



Cephalosporium sp. 



Natural vector. — Periplaneta americana, U.S.A., Texas (McShan, 

 unpublished MS., 1953) : From feces of cockroaches collected in the 

 basement of a grain elevator at the docks in Galveston. 



* Geotrichum candidum Link 



Experimental vector. — Blatta orientalis, Italy (Cao, 1898) : Organ- 

 ism retained its pathogenicity after passing through the insect's gut. 



Penicillium sp. 



Natural vector. — Blaberiis craniifer, U.S.A. (Wedberg et al., 

 1949) : From feces. 



Periplaneta americana, England (Bunting, 1956) : Mostly from 

 imperfectly excreted feces. 



Metarrhizium anisopliae (Metschnikoff) Sorokin 



Natural liosfs. — Blattidae, Seymour (1929) ; Charles (1941). 



Panestkia australis, U.S.A., Massachusetts (Roth and Willis, un- 

 published data, 1957) : Growing on adult specimens that were found 

 dead in a laboratory colony. Determination by Miss Dorothy Fennell. 



Periplaneta americana, England (Bunting, 1956) : Growing on 

 genitalia of females where it prevented oothecal formation. 



Cockroach, Puerto Rico (Johnston, 191 5) : From a "small roach" 

 in the pathological collection at Rio Piedras (no data). 



