CHAPTER NINE 

 EMENDMENTS TO THE DESCRIPTION OF BURENELLA DIMORPHA 



The vegetative stages of B. dimorpha were described 



by Jouvenaz and Hazard (1978) from light microscope studies 



as follows: 



Burenella dimorpha appears to have two sequences 

 of merogony. The first involves uninucleate 

 cells with deeply staining cytoplasm (Giemsa) 

 and compact nuclei that become binucleate and 

 divide. The second sequence involves binucleate 

 cells with moderately staining cytoplasm and 

 less dense nuclei that become tetranucleate and 

 divide to produce two binucleate cells- (p. 27) 



The accuracy of this description is challenged by the follow- 

 ing considerations. 



Studies on the transmission of B. dimorpha have demon- 

 strated that only the NMB spores are infective for fire 

 ant larvae (see Transmission and Infectivity of Spores). 

 The NMB spores are diplocaryotic (Fig 32); therefore, the 

 infecting sporoplasm is (presumably) also diplocaryotic. 

 The formation of uninucleate meronts would require either 

 fusion of the sister nuclei or separation of the nuclei 

 followed by cell division. Studies of Nosema spp. (Sprague 

 et al., 1968; Vavra and Undeen, 1970; Call, 1971) and an 

 Amblyospora sp. (Andreadis and Hall, 1979) indicate that in 

 these species, the diplocaryotic condition persists throughout 

 the life cycle. 



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