76 



Mycologia 



tissues in the posterior segments of the body of the host, ulti- 

 mately destroys all such tissues, including the flexible interseg- 

 mental membranes of the abdomen in this region. As a result of 

 the complete destruction of these membranes the posterior ab- 

 dominal segments slough off until a condition such as that illus- 

 trated on Plate 5, Figs. 1 B and C is reached. The sloughing off 

 process takes place progressively, beginning with the last segment 

 and continues until four or more have been dropped, the last re- 

 maining one marking the position of the septum referred to above. 

 The insect does not die at the time the first segments are dropped. 

 On the contrary it remains alive for a considerable period and 

 continues to fly and crawl about from place to place. 



As far as the writer is aware such a sloughing off process, tak- 

 ing place while the host is alive, is quite unknown in other insects 

 attacked by other members of the Entomophthorales, and in fact 

 the phenomenon is so unusual that it has been noted by practically 

 every person who has observed the disease in the field. The ap- 

 pearance of insects crawling and flying about with but two or 

 three abdominal segments attached to the thorax, is indeed suf- 

 ficiently striking to attract the attention of any one. 



The fungus mass, including the conidia, which morphologically 

 is of endogenous origin, becomes exposed as fast as the body seg- 

 ments of the host rot away, and the movements of the insect from 

 place to place serve to disseminate the conidia in a way that could 

 scarcely be improved by any natural method. It will be recalled 

 that in most of the entomogenous entomophthorales, the conidia 

 are borne upon conidiophores which bore their way outward 

 through the body wall of the host, and that they are violently 

 ejected from the conidiophores only after the host is dead and 

 therefore stationary. Although the conidia are thrown to some 

 distance, such a method seems inefficient when it is compared 

 With the process which takes place in the present instance, in 

 which the live, actively moving infected host mingles promiscu- 

 ously with its fellows. 



The fungus when intact forms a clay colored pustule like, 

 granular mass at the tip of the abdomen. In certain individuals 

 such as is shown on Plate 5, Fig. 1 C the pustule is quite large, 



