NO. 79. 



SB 



818 



C578 



ent nted States Department of Agriculture, 



BUREAU OF ENTOMOLOGY, 



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



THE BROOD DISEASES OF BEES. 



By E. F. Phillips, Ph. D., 

 Apicultural Expert. 



In view of the widespread distribution of infectious brood diseases 

 among bees in the United States, it is desirable that all bee keepers 

 learn to distinguish the diseases when they appear. It frequently hap- 

 pens that an apiary becomes badly infected before the owner realizes 

 that any disease is present, or it may be that any dead brood which 

 may be noticed in the hives is attributed to chilling. In this way dis- 

 ease gets a start which makes eradication difficult. 



There are two recognized forms of disease of the brood, designated as 

 European and American foul brood, which are particularly virulent. In 

 some ways these resemble each other, but there are certain distinguishing 

 characters which make it possible to differentiate the two. Reports are 

 sometimes received that a colony is infected with both diseases at the 

 same time, but this is contrary to the experience of those persons most con- 

 versant with these conditions. While it may be possible for a colony 

 to have the infection of both diseases at the same time, it is not by any 

 means the rule, and such cases are probably not authentically reported. 

 Since both diseases are caused by specific bacilli, there is absolutely 

 no ground for the idea held by some bee keepers that chilled or starved 

 brood will turn to one or the other of these diseases. Experience of 

 the best practical observers is also in keeping with this. For a discus- 

 sion of the causes of these diseases the reader is referred to Technical 

 Series, No. 14, of the Bureau of Entomology, "The Bacteria of the 

 Apiary, with Special Reference to Bee Diseases," by Dr. G. F. White. 



AMERICAN FOUL BROOD. 



American foul brood (often called simply " foul brood ") is distributed 

 thru all parts of the United States, and from the symptoms published in 

 European journals and texts one is led to believe that it is also the 

 prevalent brood disease in Europe. Altho it is found in almost all sec- 

 tions of the United States, there are many localities entirely free from 

 disease of an}' kind. 



The adult bees of an infected colony are usually rather inactive and 

 do little toward cleaning out infected material. When the larvae are 

 first affected they turn to a light chocolate color, and in the advanced 

 stages of decay they become darker, resembling roasted coffee in color. 



