CHAPTER X 

 ENTOMOPHTHORALES 



Mycelium is less profusely developed in this order than in 

 the Mucorales, and is more characteristically septate. Though 

 in a few species it persists to maturity as a filamentous branching 

 thallus, there is the tendency in the majority of forms for the 

 hyphae to be limited in development and to fall apart early at 

 the septa into the component cells. These hyphal segments 

 are then termed hyphal bodies. They increase in number 

 rapidly by fission and budding. The cells of the thallus are 

 usually plurinucleate, but in the genus Bcusidiobolus are typically 

 uninucleate. 



The majority of species are parasitic on insects, and relatively 

 few of these have ever been obtained in culture on artificial 

 media. Consequently, obligate parasitism has been assumed 

 to be predominant in the group. In recent years some degree 

 of success has attended attempts to get these forms in culture, 

 and it now seems probable that many of them will be found to 

 develop saprophytically when favorable media are provided 

 (Sawyer, 1929). Although the group is chiefly entomogenous 

 a few species are parasitic on plants, and several forms are true 

 saprophytes wholly lacking in parasitic tendencies. 



In asexual reproduction conidia are abjointed at the tips 

 of simple or indefinitely branched clavate conidiophores, and, 

 except in Massospora, are forcibly discharged, the phenomenon 

 being strikingly similar to that exhibited in Pilobolus of the 

 preceding order, where a multispored sporangium is shot away. 

 The conidium is in all cases unicellular, and is assumed to be 

 the homologue of the sporangium present in preceding groups. 

 In Basidiobolus, in the case of one of the two species comprising 

 the genus, it has been shown recently that the "conidium, " after 

 being ejected, functions as a sporangium by the production 

 of endogenous spores. In all other cases, as far as known, 

 the conidium germinates by a tube, which grows directly into 

 mycelium or cuts off a secondary conidium which is in turn 



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