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158 



EIGHTH ANNUAL REPORT OF THE 



foul brood, which causes the greatest 

 loss to the bee-keeping industry has 

 been demonstrated to be caused by 

 bacteria. Above all I would have you 

 understand that the death of the 

 brood is due to one species of bacteria 

 growing in the larvae. 



Protozoa. — In contrast to bacteria, 

 the protozoa belongs to the animal 

 kingdom. They are very small uni- 

 cellular animals. Many species are 

 harmless as are many species of bac- 

 teria, while some species, as some 

 bacteria, have the power to produce 

 disease. They produce disease and 

 death in a manner very similar to bac- 

 teria, that is by growing in the body 

 of a living animal. As far as we 

 know, none of the bee diseases are 

 due to protozoa. One investigator de- 

 scribed what he thought was a pro- 

 tozoon and named it Spirochaeta apis. 

 It was shown that he made an error 

 in his. observations. Therefore there 

 is no spirochaeta apis and no pro- 

 tozoon, as far as we know, which is 

 pathogenic to bees. 



Fungi. — This is rather a broad term 

 but in the diseases of animals we 

 usually refer, in speaking of fungi, to 

 that form of plant life which is higher 

 than bacteria. They are usually made 

 up of branching mycelial threads and 

 have a variety of methods for produc- 

 ing spores. One writer described one 

 species, Aspergillus pollini, which he 

 was supposed to have proven to be 

 the cause of pickled brood, but he 

 had not done so. 



To the above groups belong the 

 known exciting causes. There are 

 also unknown exciting causes. When 

 the unknown causes become known, 

 they may be found to belong to the 

 groups mentioned above. 



There is a very important classifica- 

 tion of diseases into those which are 

 infectious and those which are non- 

 infectious. From what has been said 

 this classification becomes clear to us. 



An infectious bee disease is one 

 which may be transmitted from one 

 colony to another through the natural 

 processes in the apiary. American 

 foul brood and European foul brood 

 are examples of this class of disease. 

 What is transmitted in an infectious 

 disease? It is the exciting cause of 

 that disease. In American foul brood 

 it is one species of bacteria, Bacillus 

 larvae. In European foul brood, we 

 do not know what is transmitted. 



Since we do not know the exciting 

 cause, it must be classed under the 

 unknown exciting causes. When the 

 cause is determined, it will probably 

 belong to one of the three groups of 

 microorganisms mentioned under the 

 known causes. 



A non-infectious disease is one 

 which is not transmitted from one col- 

 ony to another. The so-called pickled 

 brood and paralysis, as far as we 

 know, illustrate this class of diseases. 

 This brief discussion of the etiology 

 of disease is given in order that you 

 may get a clearer idea of the nature 

 of disease and what is meant by etiol- 

 ogy. We shall now consider treat- 

 ment of disease and illustrate with 

 bee diseases. 



The Treatment of Disease. 



Those who are familiar with bee 

 diseases are also familiar with the 

 different methods of treatment. It is 

 not my purpose to discuss any of the 

 classical methods, but to suggest a 

 few of the principles upon which such 

 methods must be based if they are to 

 be most effective. Treatment is both 

 preventive and; curative. 



Preventive Treatment. — Too many 

 believe that treatment of bee diseases 

 consists in the control of eradication 

 of a disease after it is found in the 

 apiary. That is only the minor part 

 of treatment curative. The treatment 

 which is of major importance is the 

 preventive treatment. Prevention is 

 much easier than cure. To prevent 

 disease in the apiary is to keep it out. 

 To keep it out is to keep out the ex- 

 citing cause. In order to keep out 

 the exciting cause, it is desirable to 

 know its distribution or where it is 

 found. In American foul brood, the 

 exciting cause. Bacillus ^ larvae, is 

 found in immense numbers in the 

 body of the diseased or dead larvae. 

 These dead larvae, for the most part, 

 are allowed by the bees to remain in 

 the brood cell as a scale. The honey 

 also has been demonstrated to contain 

 the bacteria which produce this dis- 

 ease. The pollen may be contam- 

 inated with the spores of this disease- 

 producing organism. The combs from 

 an apiary affected with American foul 

 brood are a fruitful source of infec- 

 tion. The inside of the hives which 

 have contained colonies suffering with 

 American foul brood may be contam- 

 inated with the germs which produced 

 the disease. Honey extractors, honey 



