51 



These epidemics of the disease usually occur during warm, wet 

 weather, or after such conditions of climate have been prevailing for 



several weeks in succession. They are also quite apt to develop 

 among the insects living along the edges of irrigating ditches or on 

 grounds which have been thoroughly watered, rather than on those 

 which are comparatively high, dry. and more or less widely removed 

 from water or rank, succulent vegetation. 



Early in 1896 (March) the subject of utilizing locust-attacking fungi 

 as a means of destroying these insects came more prominently before 

 the public. In South Africa, where two species of these insects had 

 been a pest for several years, it was found that a disease of a virulent 

 nature had broken out and was prevalent in the form of an epidemic 

 among the swarms in certian localities. An investigation instituted at 

 the time showed this disease to be due to the presence of one of these 

 species of fungi. Armed with the assurance that other insects had 

 been successfully inoculated and destroyed by fungous diseases in 

 Europe and the United States, members of the stall' of the Bac- 

 teriological Institute in that country took the matter in hand and 

 were successful in their attempts to isolate a fungus which was thought 

 to be the one that was destroying the insects in question, a species of 

 large migratory locust (Acridium purpuriferum Walk.). A brief 

 account of the methods followed and results obtained from this work 

 is given by Alexander Edington, the director, in his annual report for 

 1898 of the Colonial Bacteriological Institute, located at Grahamstown, 

 Cape of Good Hope. 



A year or so later (June, 1897), during investigations that were being- 

 made at the time in connection with the large migratory locust of the 

 Argentine Republic {Schistocerca para ru ensis Burm.), the writer dis- 

 covered what appeared to be still another and quite distinct species of 

 these locust-destroying fungi — a Sporotrichum. This discovery was 

 made at Carcarana, a little toAvn in southern Santa Fe. on the Central 

 Argentine Railway, and some experiments conducted later during the 

 same year demonstrated its usefulness, under certain limitations, as a 

 means of combating that insect. The South African fungus referred 

 to above was also tried on tin 4 same locust, but with exceedingly poor 

 results so far as could be ascertained at the time. Still more recent 

 attempts at destroying various kinds of our North American locusts 

 with both of these fungous diseases (South African and Argentinian) 

 have resulted in no marked degree of success, so far as the writer is 

 concerned at Least. 



During the past two or three years other persons have been con- 

 ducting similar experiments with these same, and apparently some 

 other, locust-killing fungi. A few oi' these recent experiments carried 

 on by other workers seem to have proven more successful than those 

 just mentioned above. One in particular appeared to be very prom- 



