A SYSTEMATIC STUDY OF THE ORGANISMS DIS- 

 TRIBUTED UNDER THE NAME OF COCCOBAC- 

 ILLUS ACRIDIORUM D'HERELLE. 



By R. W. Glaser, 

 Of the Bureau of Entomology, U. S. Department of Agriculture.* 



A large amount of work has lately appeared dealing with 

 d'Herelle's Coccobacillus acridiorum and his method of com- 

 bating noxious grasshoppers. Some investigators have been 

 able to confirm d'Herelle's results; others have been unable to 

 do so, and since the entire subject seems to be in a state of 

 confusion, I undertook a systematic study of a number of 

 cultures which I obtained and which were distributed under 

 the name of Coccobacillus acridiorum d'Herelle. As I suspected, 

 some of the separate cultures proved to represent either different 

 species or varieties of the same species. This fact may account 

 for some of the contradictory views held by so many workers 

 and it is my hope that this article will also demonstrate the 

 need for attention to the ordinary principles of bacteriology 

 which seem to be so persistently neglected by many 

 entomologists. 



In 1909 Dr. F. d'Herelle, while in the State of Yucatan, 

 Mexico, noticed a heavy mortality in some flights of the 

 destructive South American migratory locust Schistocerca 

 americana Drury which arrived in the State from the borders 

 of Guatemala. In 1911 the flights were all visited by this 

 epizootic and by 1912 it had reduced the number of locusts to 

 such an extent that no invasion into Mexico occurred. In 

 1910 d'Herelle isolated a bacterium from the intestinal contents 

 of cases of this disease. The organism was named by him 

 Coccobacillus acridiorum. He was able to reproduce the disease 

 and death by inoculating healthy grasshoppers with a culture 

 of the Coccobacillus. These results were thought to be impor- 

 tant by the Republic of Argentine which in 1911-12 requested 

 d'Herelle to study the action of his bacterium against Schisto- 

 cerca paranensis Burm, with a view towards its possible use in 

 combating the pests. D'Herelle's methods apparently proved 

 highly successful. 



*In co-operation with the Bussey Institution of Harvard University (Bussey 

 Institution No. 139). 



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