UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 810 



Contribution from tlic Bureau of Entomolugy 

 L. O. HOWARD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



February 26, 1920 



EUROPEAN FOULBROOD 



By G. F. Whitf; 

 Specialist in Insect Diseases 



Introduction 



Name of the disease 



Healthy larvae of the age at which 



thej' die of European foulbrood 



Symptoms 



Etiology 



Technique 



Thermal death point of Bacillus 



pluton 



Resistance of Bacillus pluton to 



drying 



tlesistance of Bacillus pluton when 



dry to dire.ct sunlight 



Resistance of Bacillus pluton in 



water to direct sunlight 



Resistance of Bacillus pluton in 



honey to direct sunlight 



CONTENTS 



Page 

 1 



17 



17 



19 



20 



21 



Resistance of Bacillus pluton to fer- 



menta,tion 



Resistance of Bacillus pluton to 



putrefaction 



Viability of Bacillus pluton in honey_. 

 Viability of Bacillus pluton in pollen_ 

 Resistance of Bacillus pluton to car- 

 bolic acid 



Effect of drugs on European foul- 

 brood 



Transmission of European foulbrood- 



Diagnosis 



Prognosis 



Summary and conclusions 



Literature cited 



Explanation of plates — 



Page 



21 



22 

 23 

 24 



24 



26 

 26 

 28 

 31 

 31 

 34 

 37 



INTRODUCTION 



European foulbrood is an infectious disease of the brood of bees 

 caused by Bacillus pluton. It is characterized by the death of brood 

 during its uncapped stage and by the absence of any marked odor. 

 The disorder has a wide distribution and is fairly well known to bee- 

 keepers. The losses sustained by the infected apiary vary from a 

 slight weakening of the colonies in some instances to the destruction 

 of all of them in others. 



Practical apiarists have determined mucn concerning the disorder 

 while pursuing their profession. The writer in an earlier paper (15)^ 

 referred to the nature and extent of the progress that had been made 

 in the study of the disease from the laboratory point of view. The 

 present paper deals with results which have been obtained from a con- 

 tinuation of the work. Among the problems considered are : The re- 



'■ Figures in parentheses refer to " Literature cited," p. 34. 

 182817°— 20— Bull. 810 1 



