STUDIES ON COCCOBACILLUS ACRIDIORUM 



D'HERELLE, AND ON CERTAIN INTESTINAL 



ORGANISMS OF LOCUSTS. 



By E. Melville Du Porte and J. Vanderleck, 

 Macdonald College (McGill University). 



PART I. EXPERIMENTS ON THE CONTROL OF LOCUSTS BY THE USE 

 OF COCCOBACILLUS ACRIDIORUM d'h. 



A . Historical Resume. 



Coccohacillus acridioriim, the causal organism of an epi- 

 zootic disease of locusts, was isolated in the State of Yucatan, 

 Mexico, in 1910, by Dr. F. d'Herelle from the South American 

 migratory locust Sckistocerca americana Drury. He had observed 

 that during the previous year the swarms migrating northward 

 into Mexico from the confines of Guatemala showed evidence of 

 the presence of an epizootic. The mortality in the swarms 

 increased each year until 1912, when the disease had destroyed 

 the locusts to such an extent that no swarms migrated into 

 Mexico. D'Herelle was able to produce disease and death by 

 inoculating healthy locusts with a culture of the organism which 

 he isolated from the diseased locusts. The results of his exper- 

 iments led him to believe that the use of this organism would 

 have successful results in the control of locusts. 



In 1911-12 he was given an opportunity to test the effective- 

 ness of his cultures against Schistocerca paranensis Burm. in the 

 province of Santa Fe, Argentina, where his attempts met with 

 a decided success. 



Results obtained by Sergent and Lheritier in Algeria during 

 1913 were not conclusive. They found that Dociostaurus 

 maroccaniis Thunberg was susceptible to the disease, but the 

 epizootic did not spread with sufficient rapidity to cause 

 appreciable diminution in the size of the swarms. They attrib- 

 uted their failure to three contingencies, either the infection 

 did not spread through the greater portion of the migrating 

 swarm, or many of the locusts possessed a natural immunity, or 

 else they easily acquired an active immunity against the 

 organism. 



Lounsbury in 1913 conducted experiments in South Africa 

 to determine whether C. acridiorum could be effectively used in 

 combating the non-migratory Zonocerus elegans. His exper- 



47 



