64 EXPEKIMENT STATION RECORD. 



1707-1709).— In Investigations conducted in May, 1912, the anthor found Cocco- 



'bacillus acridiorum to cause the death of cockchafers in from 2^ to 48 hours 

 when injected into the body cavity. When ingested, however, it does not 

 affect the coclichafer. 



The author also found a septicemia to be caused by a coccobacilUis {Bacillus 

 melolonthcB). This is much similar to C. acridiorum, but differs in a constant 

 manner both in its morphological and cultural characteristics, including a some- 

 what greater length and the production of fluorescence in gelatin after cultiva- 

 tion for 5 or 6 days, and also by its pathogenic action on the silkworm. When 

 injected into the body cavity an uncultivated virus killed the cockchafer in 

 from 12 to 24 hours, but when ingested it is innocuous. B. melolonthoe was 

 found in the digestive tract of 75 per cent of healthy cockchafers, in some cases 

 in great numbers, as is always the case in septicemic specimens. Thus the 

 septicemia appears to be of intestinal origin, as occurs in the locust. It was 

 found that the silkworm possesses a complete natural immunity against G. 

 acridiorum, while B. melolonthce is as virulent in the silkworm as in the cock- 

 chafer when injected and as inactive when ingested. 



Another coccobacillus (B. homhycis) proved to be the cause of a septicemia 

 in the silkworm. During the rearing of some 2,000 worms from 5 to 10 indi- 

 viduals are said to have succumbed daily to this disease. In its morphology 

 this bacillus resembles B. melolonthw, but it does not form fluorescence in gelatin 

 and is clenrly differentiated from C. acridiorum by its greater virulence. Like 

 B. melolonthw it proves fatal to the silkworm in from 12 to 24 hours when 

 injected into the body cavity. By ingestion the author infected 4 out of 27 

 individuals. Thus it is more virulent than either B. melolonthw or C. acrid- 

 iorum, but is much less widely distributed and abundant in the digestive tube 

 of healthy silkworms than is B. melolonthw in the cockchafer. See also a 

 previous note (E. S. R., 29 p. 855). 



In this disease of the silkworm, which has previously escaped recognition, 

 no external symptoms are noticed before death. The coccobaciUosis, a^ termed 

 by the author, is essentially different from the well-known flacherie, grasserie, 

 and polyhedral body disease. 



The coccobacilli infections of insects, F. Picaed and G. R. Blanc (Compt. 

 Rend. Acad. Sci. [Paris], 157 {1913), No. 1, pp. 79-81; abs. in Rev. Appl. Ent., 

 1 {1913), Ser. A, No. 9, pp. 336, 337). — In further investigations of its path- 

 ogenicity (E. S. R., 29, p. 855), Coccobacillus cajw was found to cause the death 

 of various Coleoptera, Hemiptera, Orthoptera, and Lepidoptera into which it 

 was injected, including the cockchafer, brown-tail moth, silkworm, etc. During 

 the course of examinations made of the gipsy moth, which was unusually 

 abundant in southern France during the year, the authors discovered a cocco- 

 bacillus, causing a fatal septicemia, which they name Bacillus lymantruE. In 

 investigations conducted it was found possible to kill Arctia caja caterpillars 

 with a few drops of a culture of G. cajw when introduced into the pharynx by 

 means of a pipette without flnding a trace of the organism in the blood. It is 

 pointed out that G. cajw, B. bombycis, B. melolonthw, and B. lymantriw differ 

 from G. acridiorum in that the last-named is fatal to the locust when ingested 

 but innocuous to the silkworm. 



Locust bacterial disease, C. P. Lounsbuey {Agr. Jour. Union So. Africa, 5 

 (1913), No. J^, pp. 607-611). — This is a report of experiments with Gocco- 

 bacillus acridiorum in which the so-called "elegant grasshopper" {Zonocerus 

 elcgans), a nonmigratory species, was used as migratoi*y locusts were not 

 available. The results led the author to conclude that this disease at best can 

 be employed only as a supplementary measure in dealing with an invasion of 

 locusts under the conditions that prevail in South Africa. 



