A TEST OF COCCOBACILLUS ACRIDIORUM D’HERELLE ON 
LOCUSTS IN THE PHILIPPINES * 
By MARSHALL A. BARBER and CHARLES R. JONES 
(From the Biological Laboratory, Bureau of Science, and the Entomological 
Division, Bureau of Agriculture, Manila, P. I.) 
In view of the reported success following the use of Cocco- 
bacillus acridiorum d’Herelle in the destruction of locusts in 
Argentina, South America, it was deemed advisable to test the 
method in the Philippine Islands. 
It may be stated at the outset that we are unable to obtain 
any results of practical value, but in view of the number of ex- | 
_ periments made and the thoroughness of the trial, it has seemed 
worth while to record our negative results. 
A sealed agar culture, arriving in perfect condition, was re- 
ceived in May, 1913. It bore the label of the Pasteur Institute, 
and complete directions for its use were sent with it. Following 
the directions, we proceeded to exalt the virulence of the culture 
and to inoculate a series of locusts with a broth culture of the 
bacillus. Subsequent lots were inoculated with material taken 
from dead or dying insects of the preceding series, and so on. 
The locusts chosen were adults, fairly fresh from the field, and 
the inoculated ones and controls were kept in large cages and 
were supplied with food. A layer of white filter paper on the 
bottom of each cage served to reveal the presence of diarrheal 
feces. In inoculation a fine-pointed glass pipette was used in- 
stead of a syringe, since the former appeared more convenient — 
to handle and allowed a more accurate dosage. The technique 
followed was a modified form of a technique used by one of us’ 
in the inoculation of cockroaches with plague bacilli. Inocula- 
tions were made into the abdomen as directed, and dilutions 
were made with broth in later transfers. Practically every dose 
was examined microscopically, and cultures were made at each 
inoculation. 
Several exaltation series were carried out. In one, carried to 
the thirtieth set of insects, we used for the most part diluted 
* Received for publication November 13, 1914. 
* This Journal, Sec. B (1912), 7, 521. 
132716——5 163 

