BROOD DISEASES IN ENGLAND: 



THE RESULTS OF A THREE-YEAR 



INVESTIGATION 



By H. L. A. Taer, Ph. D. 

 (Rothamsted Experimental Station, Harpenden, Herts.) 



In the time available it will only be possible to summarize briefly 

 the results which have been obtained since the inception of the 

 brood disease research scheme at Rothamsted. In doing this it 

 will be necessary to assume some knowledge of the common 

 characteristics of the various brood diseases : so much has been 

 said and written about them recently that this demand would not 

 appear unfair. The fact that there is indeed a multiplicity of brood 

 diseases in England must be emphasised. Statements to the contrary 

 have been and are being made by individuals who occupy promin- 

 ent positions in beekeeping in this country : such statements are 

 definitely erroneous. The fact that there is a multiplicity of brood 

 diseases is of considerable importance when one has to consider 

 their treatment. 



Since May, 1934, two hundred and five samples of diseased 

 brood have been sent to the laboratory and the following diagnoses 

 have been made : American foul brood, 104 ; Addled brood, 58 ; 

 European foul brood, 13 ; Chalk brood, 11 ; American foul brood 

 and Addled brood, 1 ; American foul brood and Chalk brood, 1 ; 

 chilled or neglected brood, 4 ; spray poisoning, 1 ; Sac brood, 4 ; 

 drone laying queen and decomposing brood, 5 ; and drone laying 

 queen and Chalk brood, 3. Though it cannot be stated that these 

 figures denote the actual proportion of brood diseases in England, 

 they certainly are of value in that they give some indication of their 

 distribution, the proportion being relatively constant from year 

 to year. It is practically certain that the distribution of the different 

 diseases could not have been foretold prior to the commencement 

 of the investigation. So far most of the time has been devoted to 

 experiments designed to determine the causes of the three most 

 prevalent brood diseases, for without this knowledge it would be 

 difficult to devise treatment. The results of experiments relating 

 to the different diseases will be discussed separately. 



