UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 810 



Contribution from tlie Bureau of Entomology 

 L. O. HOWARD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



February 26, 1920 



EUROPEAN FOULBROOD 



By G. F. White 

 Specialist in Insect Diseases 



CONTENTS 



Page 



Introduction 1 



Name of tlie disease 2 



Healthy larvse of the age at which 



they die of European foulhrood 3 



Symptoms 4 



Etiology 7 



Technique 13 



Thermal death point of Bacillus 



pluton 17 



Resistance of Bamllua pluton to 



drying 17 



Besistance of Bacillus pluton when 



dry to direct sunlight 19 



Besistance of Baolllus plutoi in 



water to direct sunlight 20 



Besistance of Baeillus pluton in 



honey to direct sunlight 21 



Page 

 Besistance of Bacillus pluton to fer- 

 mentation 21 



Besistance of Badttus pluton to 



jlutrefaction 22 



Viability of Bamllus pluton in honey_- 23 

 Viability of Ba^llus pluton in pollen_. 24 

 Besistance of Baolllus pluton to car- 

 bolic acid 24 



Effect of drugs on European foul- 

 brood 26 



Transmission of European foulbrood- 26 



Diagnosis 28 



Prognosis 31 



Summary and conclusions 31 



Literature cited 34 



Explanation of plates — . 37 



INTRODUCTION 



European foulbrood is an infectious disease of the brood of bees 

 caused by BaciUus 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- 



132817° 



' Figures in parentheses refer to 

 -20— Bull. 810 1 



' Literature cited," p. 34. 



