MICROBIOLOGY OF DISEASES OF INSECTS 649 



Septicemia of the Cockchafer, Melolontha vttlgaris 

 Bacillus melolonthm — Chatton* 



History. — ^In May 1912, while studying the efifect of d'Herelle's 

 B. acridiorum on the cockchafer, Chatton noticed that the cockchafers 

 were d5dng from a spontaneous septicemia; this he found later was due 

 to a coccobacillus which he named B. melolontha. 



Symptoms. — No symptoms are noted. 



Causal Organisu. — B. mdolonthcB resembles B. acridiorum of d'Herelle with the 

 exception of the following characteristics: the bacillus is longer, and in agar culture 

 produces a green fluorescence in five to six days. It is distinguished from the bacillus 

 of d'Herelle in addition by its pathogenic action on the silk- worm, Bomhycis mori. 



Methods of Infection. — Injected into the general cavity, B. 

 melolontha kills the cockchafer in twelve to thirty-six hours, and where 

 its virulence has been augmented by several passages through this 

 insect, always in less than twenty-four hours, but per os it is as 

 inactive as B. acridiorum. Seventy-five per cent, of healthy cock- 

 chafers show the presence of B. melolontha in their digestive tube, 

 sometimes in massive culture. This is always the case with cock- 

 chafers affected with septicemia. 



This blood disease seems to be of intestinal origin however, as with 

 the locust. B. melolontha,^ common parasite of the intestine of the 

 cockchafer passes into the general cavity only under special conditions 

 yet unknown. When this organism is removed from the intestine and 

 injected into the general cavity, septicemia is produced. 



It is as virulent for the silk-worm by injection as for the cockchafer, 

 and as inactive by ingestion. 



European Foul Brood 

 Bacillus pluton — Whitef 



EbsTORY and Distribution. — ^This type of foul brood, sometimes 

 known as "black brood," or "New York bee disease" is not nearly as 

 wide spread in the United States as is American foul brood, but in cer- 



* Chatton, E. Spontaneous septicemia in the cockchafer and the silk worm due to cocco- 

 bacilK. Compt. rend., acad. sci. 156, 1913. PP- 1707-1709. 



t White G. F. The cause o£ European foul brood. Cir. 157, B. of Ent. U. S. Dept. of 

 Agr. igi2. 



