164 EXPERIMENT STATION RECORD. [Vol. 40 



On a new method of ascertaining the parasites of the respective host in- 

 sects in a mixed infestation, I. Tragardh (Bui. Ent. Research, 9 (1918), Xo. 1, 

 pp. 75-79, figs. 5). — A method which enabled the author to ascertain the rela- 

 tion of the cone insects to one another in the investigations above noted is 

 described. 



Arsenate of lime, G. E. Sanders (Canada Dept. Apr., Ent. Branch Crop 

 Protec. Leaflet 10 [1918], pp. 4). — The use of this arsenical as a spray for 

 apple, potato, and pear is discussed. It is pointed out that when the cost is 

 taken into consideration arsenate of soda is the only arsenical insecticide that 

 approaches arsenate of lime as a potato poison. 



The present status of investigations of Coccobacillus acridiorum, B. Bar- 

 i;ai:a (Rev. Inst. Bart. [Argentina], 1 (1917), Xo. 1, pp. 107-118; aba. in Rev. 

 ApijI. Ent., Ser. .1, 6 (1918), Xo. 5. pp. 177, 178).— Tins paper reviews the experi- 

 mental work conducted with a view to determining the value of C. acridiorum 

 in the destruction of locusts. The author's conclusions are as follows: 



The coccobacillus considered by d'Herelle as the cause of the epizootic in 

 Yucatan in 1909 is Innocuous to the locust after passing a certain length of 

 time in culture media. The organism can, however, be rendered more virulent 

 by its passage through locusts, until it is capable of killing these by Injection 

 in 1 or 6 hours. This virulence is rapidly lost when the organism is exposed 

 to an exterior medium. This virulence, according to the Argentine Commission, 

 is not sufficient to destroy Locusts even when the culture is ingested by them in 

 enormous quantities; even at its best the coccobacillus destroyed only 40 per 

 cent in these circumstancea 



A systematic study of the organisms distributed under the name of Cocco- 

 bacillus acridiorum, It. \V. »li LS I I Inn. Ent. Soc. Annr., 11 (1918), Xo. l, }l p. 

 19-42). — The author reports upon a study made of four cultures, one supposed 

 to represent 0. acridiorum from Honduras where striking results are claimed 

 to have been obtained witb it in field experiments, two supposed to be 0. 

 acridiorum labeled "Souche Cham" and "Souche Sidi" from d'Herelle at the 

 Pasteur Institute. Paris (the first said to be identical with that received from 

 Honduras, and the second representing a strain of 0. acri<lioriun past 

 through a series of grasshoppers in Tunis in 1915), and one supposed to be 

 C. acridiorum from Canada, where it had been used in experimental work. 

 The four cultures were found to differ from one another more or less, and a 

 table is given which shows the most striking differences and similarities. 



The bacterium from Honduras was found to represent a new form and is 

 described under the name Bacillus poncei. The author concludes from experi- 

 mental work with B. poncei that it is pathogenic to Melanoplus fanur-riibriun 

 and Encoptolophus sordidus, but in most cases he failed to recover the or- 

 ganism from the blood, alimentary tract, and feces. Experiments led him to 

 believe that insects can develop immunity principles which can more or 1 

 successfully cope with certain foreign organisms. He concludes that passage 

 infectious performed hy using the alimentary tract are hopeless on account of 

 the extensive flora. Blood passages with B. poncei were likewise useless, in 

 most cases, for the reason that the gut ruptured after a short time. 



In experiments the culture "Souche Cham" was pathogenic to M. Otlanit, 

 If. bivittatua, and M. fvinur-rubrum, being most so for the first mentioned. 

 Passage Infections with it were possible, but no Increase in virulence was ob- 

 served. "The gut of M. atlania does not rupture, and for this reason the Mood 

 and muscle tissue can be used for passage Infections, Extracts from the stom- 

 ach or intestines can not be used for passage infections. In food Infections 

 the time between inoculation and death is somewhat extended. 'Souche Cham' 



