68 Transactions of the South African Philosophical Society. 



OBSEEVATIONS ON THE MOEPHOLOGY AXD CON- 

 DITIONS OF GEOWTH OF A FUNGUS PAEASITIC OX 

 LOCUSTS IN SOUTH AFEICA. 



By E. Sinclair Black, M.B., CM., D.P.H., M.A. 



Medical Officer Rotten Island. 



(Eead October, 1897.) 



In March, 1896, I had an opportunity of examining some locusts 

 brought from Eichmond, in Natal, by Mr. Arnold Cooper to the 

 Bacteriological Institute, Grahamstown, where I was at that time 

 medical officer. These locusts Mr. Cooper found dying and dead in 

 great numbers in a maize-field, many of them attached to the maize 

 stalks in a dying condition. On closely examining them he found 

 that they were all attacked by a fungoid growth, and on a microscopic 

 examination of the tissues of the dead locusts, he found the mycelium 

 of the fungus penetrating the tissues and growing in them. The 

 locust was the large red variety (Acridium purpuriferum, Walk.) 

 which had not appeared in these regions for more than thirty years, 

 and which was lamentably destructive both from its numbers and 

 voracity. Eecognising the importance of this observation Mr. 

 Cooper, accredited by the Government of Natal, brought a supply 

 of dead locusts to the Bacteriological Institute for further examina- 

 tion. But at this time several observers in various parts of South 

 Africa observed and recorded the presence of the fungus on dead or 

 dying locusts. My part in this investigation was therefore the 

 observation of the modes of growth and the morphology of this 

 fungus. 



Appearance of the Dead Locusts. 

 On the dead locusts the fungus appeared as a grey or buff-coloured 

 fur, in patches about the depression between the thorax and the 

 abdomen, and the joints between the legs and body, and the line of 

 the tracheal stigmata of the abdomen. The growth had a velvety 

 appearance and was in all cases very short. On dissecting and 

 teasing out the connective tissue beneath the integument and 

 examining this microscopically the mycelium of the fungus and 

 round or ovoid conidia were abundantly seen. I found precisely 

 the same appearances in other diseased locusts which were sent to 



