Technical Bull. No. 149 



January, 1930 



UNITED STATES DEPARTMENT OF AGRICULTURE 

 WASHINGTON, D. C. 



FUNGOUS DISEASES OF THE HONEYBEE' 



By C. E. BuuNsiDE 

 Assistant Apiculturist, Division of Bee Cidtiu-e, Bureau of Entomology 



CONTENTS 



Page 



Introduction 1 



Historical _ 2 



Investigations with pathogens __ _ 4 



Descriptions and locations of apiaries used, i 



Races of bees _ __ 5 



The fungi studied _ _._ 6 



Collection of fungi from colonies and from ' 



individual bees 6 



Examination of diseased bees and isolation 



of pathogenic fungi 7 



Culture methods 8 



Pago 



Experiments with bees 11 



Preliminary inoculation with molded 



combs _ 11 



Inoculation experiments with pure cultures. 1 2 



Secondarily infected bees 16 



Results of inoculations and symptoms cf 



the diseases produced 16 



Discussion ___ 33 



Summary 33 



Literature cited 40 



INTRODUCTION 



The recognition and control of bee diseases is of prime importance 

 in the commercial production of honey. The serious bacterial dis- 

 eases of the brood have been extensively studied, and the life histories 

 of their causative organisms and the methods for control are fairly 

 well understood. There exist, however, other diseases of the brood 

 and of adult bees, seemingly of lesser consequence, the causes of 

 which are not yet known and for which satisfactory methods of 

 control have not been determined. 



The writer has shown in an earlier paper {5) ^ that a considerable 

 number of species of fungi occur regularly on adult bees, and less 

 frequently on their brood, which completely mummify all of the 

 softer tissues. Most of these species of fungi are capable of establish- 

 ing themselves on the brood combs under conditions that often pre- 



' Thia bulletin, prepared in part fulfillment of the requirements for the degree of doctor 

 of philosophy at the University of Michigan, is a joint contribution from the Bureau of 

 Entomology, U. S. Department of Agriculture, and the University of Michigan. The 

 experimental work was done in the laboratories of the department of botany of the 

 University of Michigan and the bee culture laboratory of the Bureau of Entomology at 

 Somerset, Md. The author acknowledges the valuable advice and assistance of C. H. 

 KauCfman, of the University of Michigan, under whose direct supervision this work was 

 done ; of H. H. Bartlett, of the University of Michigan ; of James I. Hambleton, senior 

 apiculturist, in charge of division of bee jsulture, Bureau of Entomology ; and of B. F. 

 Phillips, formerly apiculturist In charge of bee culture investigations. Bureau of Ento- 

 mology, and now professor of apiculture in the New York State College of Agriculture. 

 Special acknowledgments are due to Charles Thom and M. B. Church, of the Bureau of 

 iChemistry and Soils, for assistance in the Identification of the forms used. 



^Reference isi made by italic numbers in parentheses to " Literature cited," p. 40. 



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