BULLETIN 804, V, S. DEPARTMENT OF AGRICULTURE 



medicine, for the last two decades at least, this precept has been 

 gaining strength so that to-day preventive medicine stands on a par 

 with, if not above, most of the other branches of medicine. Why is 

 it not logical to apply this principle to the control of bee diseases ? 



Ever since European foulbrood of bees was first recognized (in 

 1894), in New York State, as a distinct brood disease, there have been 

 much controversy and speculation concerning the etiology of the 

 disease, the means of transmission, the method of spread, and, result- 

 ing therefrom, the question of control. From the laboratory stand- 

 point, the etiology of the disease has been worked out quite definitely 

 bacteriologically (12)^. But as yet Bacillus /J>Z'^/"^6>?^, the accepted 

 cause of European foulbrood, never has been grown in pure culture 

 on artificial media, although it has been definitely identified as the 

 cause of the disease. This precludes any further advance along this 

 line of attack for the time being. 



From the side of practical experience, there have been recorded 

 large numbers of observations, many of them of a similar nature. 

 These observations have led to many accepted practices, as, for in- 

 stance, the use of Italian bees and strong colonies in combating the 

 disease. Although the weight of numbers tends to give substantia- 

 tion to observ^ations, the scientific explanation of how these things 

 are true never has been studied carefully and coordinated with the 

 practical side into an epidemiological study of the colony under dis- 

 ease conditions in European foulbrood. 



The history of bee diseases has developed mainly along two lines. 

 The scientific side has been concerned principally with determining 

 the causes of the various diseases microbiologically, the method of 

 diagnosis, and conclusively differentiating them. These facts have 

 been described sufficiently in various bulletins of the Bureau of En- 

 tomology and will not be discussed here. From the practical side, 

 countless observations have been recorded, largely in the bee journals, 

 in which various manifestations of the disease and experiences with 

 methods of treatment have been discussed. But in all this literature, 

 particularly with regard to European foulbrood, there are few ob- 

 servations on the disease and on the behavior of the bees in relation 

 to it beyond simple description of symptoms. 



Early in the experience with European foulbrood it was learned 

 by careful observers that strong colonies are essential in successfully 

 combating the disease. Later the value of Italian bees was dis- 

 covered. West (11), a New York State apiary inspector, in giving 

 what is one of the best early descriptions of European foulbrood, 

 makes some pertinent observations on the disease. He states that 

 when diseased brood is placed above a strong, healthy colony, with 

 a queen excluder between, so that any healthy brood may emerge, 



1 Reference is made by number in parenthesis to " Literature cited," p. 28. 



