DISEASES OF BEES 35 



Most progressive beekeepers in the United States are now in 

 favour of burning. Many would not resort to the old shaking 

 treatment or the use of disinfectants. As a matter of fact, a bee- 

 keeper can use any method he sees fit. It is only the colonies found 

 infected at the time of the inspector's visit that must be burned. 

 It is not uncommon to find apiaries that have had an intermittent 

 history of disease for as long as 50 years, their first complete freedom 

 not coming imtil 3 or 4 years after application of the safe and 

 economical method of burning and burying. 



At this point it is well to go back and draw a parallel with 

 respect to developments that have taken place in scientific research 

 on American foul brood. The participation of the Federal Govern- 

 ment with respect to this disease has been confined to research. 

 After Dr. White had worked out the life history of the causative 

 organism and had given it the name Bacillus larvae, progress was 

 slow and little was added to our knowledge of the disease until 

 Dr. A. P. Sturtevant reported the results of his work dealing with 

 the development of the disease in relation to the metabolism of 

 B. larvae. This research explained why the gross symptoms of the 

 disease were so imiform ; the organism simply would not grow in 

 a medium of high sugar concentration. This in turn explained 

 why larvae of feeding age seldom fell victims to the disease ; it 

 was not until after the feeding period and the beginning of quies- 

 cence that the sugar content of the gut fell low enough to enable 

 the spores of B. larvae to germinate. The organism then dii its work 

 quickly. As a result, in American foul brood the diagnostic features 

 are extremely regular, in great contrast to the symptoms encountered 

 in European foul brood. 



Just previous to the publication of these results. Dr. Hutzelman 

 announced to the beekeeping world the success of the formalin- 

 alcohol method for disinfecting combs. Out of the tests that the 

 Department of Agriculture and some of the State universities made 

 of the Hutzelman and various other solutions came the recommenda- 

 tion for the use of formalin-water solution for disinfecting combs, 

 and this mixture was found to be fully as efficacious as formalin- 

 alcohol, if not more so. A great many beekeepers used both solutions, 

 and many samples of treated combs were submitted to the Depart- 

 ment of Agriculture for sterility tests. Judging from these, the 

 results were fairly satisfactory ; yet in apiaries in which disease 

 seemed to be carefully handled, American foul brood continued to 

 recur. In fact, the general failure of these disinfectants in the hands 

 of beekeepers helped to encourage the adoption of the more drastic 

 method, namely, that of burning. 



One of the State experiment stations, after some preliminary 

 research, recommended the use of chlorine. Again many treated 

 combs were sent to the Department of Agriculture for sterility tests, 

 and at first practically all samples appeared to be sterile. The odour 

 of chlorine, however, clung tenaciously to the treated combs. It 



