48 Annals Entomological Society of America [Vol. X, 



iments were unsuccessful as the disease did not spread in the 

 field, and he came to the conclusion that under South African 

 conditions the biological method of d'Herelle can be used only 

 as a supplementary measure and cannot supersede the use of 

 poison baits in the control of locusts. 



Oedaleus nigrofasciatus De Geer and Locusta migratoroides R. 

 and F., two injurious locusts in the Philippines, were exper- 

 imented' on by Barber and Jones in 1913. An absolute failure 

 in the field experiments was reported. 



The Entomological Branch of Canada attempted without 

 success to introduce the disease in parts of Quebec during the 

 seasons of 1913 and 1914. Owing to the fact that the culture 

 had to be sent a considerable distance from the laboratory in 

 which it was prepared, which Avould probably affect the vir- 

 ulence of the organism, no definite conclusions were reached. 



In 1914-15 Beguet, Musso and Sergent conducted a cam- 

 paign in Algeria against an invasion of Schistocerca peregrina 01. 

 using both the biological and the mechanical methods of control. 

 The combination of the two methods proved very successful. 

 The biological method could not be used to protect fields that 

 were directly menaced as the disease spread slowly. In the 

 Sebdou region two indigenous coccabacilli were found which 

 immunized the locusts against d'Herelle's organism. Similar 

 organisms were reported from Algiers. 



During 1915 a locust invasion of Tunisia threatened disaster 

 over about 36,000 square miles of territory. D'Herelle succeeded 

 in completely controlling the outbreak by means of a combina- 

 tion of the biological and mechanical methods. 



In Morocco during 1915 Velu and Bouin conducted extensive 

 experiments on the control of 5. peregrina. They concluded that 

 "d'Herelle's method gives encouraging results. Starting with a 

 sufficiently virulent culture of the coccobacillus it is possible to 

 create, either by spraying with bouillon or by contamination 

 from diseased nymphs, an epizootic which is very contagious 

 and sometimes extremely deadly, but the progress of which is 

 by no means overwhelming." They advise its judicious com- 

 bination with other methods. 



The experiments described below were conducted at the 

 request of Dr. C. Gordon Hewitt, Dominion Entomologist, 

 during the summer of 1916. The original culture used was 

 obtained by Dr. Hewitt from the Pasteur Institute at Paris. 



