20 An7ials Entomological Society of America [Vol. XI, 



D'Herelle's method consisted in obtaining a virulent form 

 of his organism by twelve successive passages and then spraying 

 dilutions of his cultures over sections of land infested by grass- 

 hoppers. The insects became infected by eating the contam- 

 inated food. The passages were performed by inoculation and 

 the organism was considered to be virulent when death occurred 

 in eight hours. The organism at its maximum virulence was 

 supposed to cause death in three hours. 



In 1913 Sergent and L'heritier tried out the efficacy of 

 Coccohacillus acridiorum against Stauroyiotus maroccanus in 

 Algeria. A general epidemic failed to develop in the field and 

 the authors suggest that this failure may have been due to the 

 presence of two autochthonous bacilli in the locusts which may 

 have had an im.munizing effect. 



Lounsbury in 1913 attempted to combat Zonocerus elegans 

 with d'Herelle's organism, in South Africa, but was unsuccessful. 



Barber and Jones in 1913 performed field experiments with 

 Coccohacillus acridiorum in the Philippines in an endeavor to 

 check the injurious Oedalens nigrofasciatus De Geer and Locusta 

 migrator aides R. and F. The experiments failed to show any 

 satisfactory results. 



During 1914-15 Beguet, Musso and Sergent conducted a 

 campaign in Algeria against Schistocerca peregrina Oliv. These 

 workers used d'Herelle's method in combination with the 

 ordinary mechanical methods used for fighting the pests. It 

 was found that d'Herelle's bacterium could not be used alone 

 for the disease spreads too slowly. The combination of the 

 two methods, however, proved helpful. 



In 1915 Rorer reported that he had performed inoculation 

 experiments with Coccohacillus acridiorum on Schistocerca par- 

 anensis and Tropidacris dux in Trinidad. He found that the 

 organism was pathogenic to both insects and that the virulence 

 could be increased by successive passages. Field experiments 

 were not attempted. 



Laines in 1915 reported that he was able to control grass- 

 hoppers in Honduras with d'Herelle's organism. A series of 

 grasshoppers was inoculated from the abdominal substance of 

 a series previously dead of the disease. By successive passages 

 in this manner he claims to have obtained a high degree of 

 virulence for the bacterium. 



D'Herelle in 1915 controlled a severe outbreak of Schistocerca 

 peregrina Oliv. in Tunisia by combining the use of his organism 

 with the mechanical methods. 



