CONIDIAL SERIES 



ENTOMOPHTHORALES (ANCYLISTES) 



A lthough the Entomophthorales are commonly thought of as a 

 ** group of insect parasites, actually they live in a diversity of habi- 

 tats and under a variety of biological relationships with their substrata. 

 Of those that are saprophytic some occur on the excrement of frogs and 

 lizards, others on fruiting bodies of higher fungi, on orchid seeds, or on 

 rotten wood, in leaf mold, and so on, and one species, Completoria 

 complens, has been found only in fern prothallia. 



The discovery by Berdan (1938) that members of the small and hither- 

 to supposedly zoosporic genus Ancylistes bore conidia has completely 

 changed our concept of their relationship. From the fact that the thallus 

 consists of a series of multinucleate segments of limited extent and may 

 produce extramatrical conidiophores, from the tips of which conidia arc 

 forcibly projected, Berdan rightly concluded that this genus belongs in 

 the Entomophthorales. The new status of these aquatic parasites of 

 desmids separates them from the small number of similar-appearing but 

 zoosporic fungi (Myzocytium, Lagena, and Lagenidium) which together 

 with Ancylistes formed the old order Ancylistales. 



All members of the order are characterized by a segmented thallus, 

 the divisions of which are usually multinucleate, and have a rather 

 coarse cytoplasm with numerous large vacuoles. The thallus segments 

 sometimes separate, their parts forming the so-called "hyphal bodies." 

 The conidia are unicellular and usually externally produced at the apex 

 of a modified hypha (conidiophore) from which they are for the most 

 part shot off into the air with considerable force. The resting spores may 

 be asexually formed or sexually after a zygomycetous type of conju- 

 gation or one that is reminiscent of an oogamous condition. 



Since concern here is only with a single genus of the family Ento- 

 mophthoraceae, Ancylistes, the discussion is confined to it. 



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