FUNGOUS DISEASES OF THE HONEYBEE 5 



bees. With the beginning of cold weather the colonies were placed 

 in an attic where a temperature of about 65° F. was maintained, 

 affording facilities for manipulating the bees during cold weather 

 without danger of chilling them. The general conditions here with 

 respect to honey flows and weather factors are essentially the same 

 as at Bronson, excepting that here the early spring honey flow is 

 somewhat heavier on account of the surrounding fruit farms. On 

 the other hand, the fall honey flow from wild flowers is somewhat less. 

 Two apiaries of the bee-culture laboratory of the Bureau of Ento- 

 mology at Somerset, Md., were used during the summers of 1924, 

 1925, and 1926. One of these was located at the laboratory, while 

 the other was about a quarter of a mile away. Forest trees, par- 

 ticularly species of Acer and Salix, provide a source of nectar dur- 

 ing early spring, but the main honey flow is from the tulip tree 

 {Linodendron, tvlipifera). Occasionally basswood (Tilia), spruce 

 (Picea), and locust {Rohinia fseudoaoacia) yield appreciable quan- 

 tities of nectar. The fall flow here is light and of short duration. 



RACES OF BEES 



The bees used for the tests for susceptibility were for the most part 

 Italians and Italian hybrids, including workers, drones, and queens. 

 No other races were used for inoculation experiments. Pathogenic 

 organisms were isolated, however, from Carniolan bees. 



The colonies used for inoculation experiments were, most of them, 

 in 5-frame hives (nuclei) containing three or more frames of 

 brood. Normal colonies in standard 10-frame hives were also occa- 

 sionally used. 



THE FUNGI STUDIED 



The fungi used were isolated from bees collected from widely 

 different sources. 



The greater number of forms were from bees from the experi- 

 mental apiaries. The first isolations of fungi were made from dead 

 bees and their brood collected at Bronson, Mich., during the early 

 brood-rearing season of 1924, and others were made from bees col- 

 lected at this same apiary during the spring of 1925 and that of 1926. 

 During the summers of the three years that this work was in progress 

 fungi were collected from the apiaries of the bee-culture laboratory 

 of the Bureau of Entomology. Among the forms obtained here were 

 duplicates of most of those collected at Bronson and elsewhere. 

 Important collections were also made from the experimental a,piary 

 at the University of Michigan during the academic years of 1924-25 

 and 1925-26. 



In addition to the collections from the experimental apiaries, fungi 

 have been isolated from samples of bees or brood sent to the bee- 

 culture laboratory from all of the important beekeeping regions of 

 the United States. Although the forms isolated from such samples 

 duplicated those obtained from the experimental apiaries, their 

 presence gave an indication of the extent of the range of these forms. 

 All of the Aspergilli in the following list appeared with sufficient 

 regularity to indicate their distribution among bees in all parts of 

 the United States, and two species, A. ftavus and A. fvmdgatus, were 

 , isolated on several occasions from bees imported from Europe. The 



