Circular No. 169. issued January 15, 1913. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



SACBROOD,' A DISEASE OF BEES. 



By G. F. White, M. D., Ph. D., Expert in Bacteriology. 

 INTRODUCTION. 



The purpose of this preliminary paper is to discuss briefly a dis- 

 ease, which has been recognized by the bee keepers for many years 

 as dead brood, that is different from foul brood. 



Sacbrood, therefore, is no new disease. Samples of it have been 

 received from all the States except three, together with samples from 

 Canada. This disease really has had no name. In recent years many 

 bee keepers have by mistake spoken of it as " pickled brood." The 

 pickled brood as William R. Howard describes it, however, is a very 

 different disease. Before considering sacbrood it might be well to 

 explain briefly what is meant by pickled brood. 



PICKLED BROOD. 



In 1896 William E. Howard, of Texas, wrote a paper in which he 

 describes a disease of bees that he calls " pickled brood." He de- 

 clared in his paper that the disease was caused by a fungus to which 

 he gave the name Aspergillus pollini. In 1898 he wrote a second 

 {japer in which he says that the fungus may attack not only the 

 larvae and pupae but adult bees as well. 



Maassen in 1906 mentioned a disease of bees which he says is caused 

 by a fungus stated by him to be similar to Aspergillus flavus and 

 easily isolated from the larvae, pupae, and adult bees affected by the 

 disease. 



These hvo men, then, Howard and Maassen, have each Avritten of 

 a disease of bees which they believe to be caused by a fungus. By 

 each it is claimed that the fungus can attack adult bees as well as the 

 larvae and pupa?. Howard named the disea.se which he mentioned 

 " pickled brood," and Maassen referred to the disease which at- 



' This circular will be followed by a bulletin of this bureau in which this disease will 

 be treated more fully. 



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