ORDEB ZOOPAGALES 



177 



rarely in America. E. grylli Fresenius is very abundant in some seasons 

 in the plains states of the United States, causing the death of* immense 

 numbers of grasshoppers which climb up on stalks of grasses and other 

 plants and there die. In moist weather their abdomens are first covered 

 by belts of conidiophores emerging from between the segments, but in 

 dry weather these are not conspicuous. Azygospores are produced in 

 great numbers in the body cavity of the host. (Figs. 61G-H, 62F-K.)^ 



Several other genera have been described, including Alassospora, 

 parasitic in the 17-year cicada (Tibicina septendecim) . In this genus the 

 conidia are produced within the host, not on extruded conidiophores, and 

 are distributed by the gradual sloughing off of the affected parts while 

 the insect is still capable of creeping around. Sexual reproduction is 

 unknown. 



Speare (1912) and Sawyer (1929) devised means of growing species 

 of Entomophthora in culture and thus have been able to follow out the 

 life histories of some species more fully than formerly. 



Order Zoopagales. The fungi tentatively brought together in this 

 order are parasitic on soil-inhabiting and aquatic animals: amoebae, 

 nematodes, and insect larvae. The hyphae are coenocytic and at first 

 nonseptate and slender. Later they develop occasional cross walls. Sexual 

 reproduction is by conjugation of short or long filaments and the pro- 

 duction of zygospores of various forms, spherical to boat-shaped. Asexual 

 reproduction is by the formation of conidia, either laterally and singly 

 or apically, in the latter case sometimes in chains. Whether these conidia 



Fig. 63. Zoopagales. (A-D) Family Harpellaceae. Harpella melusinae Leger & 

 Duboscq. (A) Vegetative hypha not yet septate. (B) Septate hypha bearing curved 

 conidia. (C, D) Formation of zygospore. (E) Family Genistellaceae. Genistella ramosa 

 Leger & Gauthier. Whole fungus with spikes of conidia and formation of young and 

 mature boat-shaped zygospores. (A-D, after Leger and Duboscq: Compt. rend., 

 188(14) :951-954. E, after Leger and Gauthier: Compt. rend., 194(26) :2262-2265.) 



