28 DISEASES OF BEES 



As we see, of the two most important brood diseases one is 

 conquered for the Swiss beekeeper, but the other still gives us much 

 concern and requires further careful research. Conditions are exactly 

 the same in the case of the two most important diseases of the adult 

 bee, which I shall discuss in a few words : — When in 1922 acarine 

 disease was discovered in our country, we were very fortunate to 

 possess in the foul brood organization a weapon with which we could 

 also control other bee diseases. Our foul brood inspectors became 

 bee disease inspectors and to the animal disease law was simply 

 added a new paragraph, " acarine disease." This immediate defence 

 has allowed us, up to the present, to save the greater part of 

 Switzerland from an acarine infection. But, in spite of the good 

 organization, our campaign would probably have been hopeless if 

 Mr. Frow had not come to our help at the right moment with his 

 treatment. In extensive scientific and practical experiments we 

 have tested this remedy and found that it actually exceeded the 

 boldest expectations and, when used correctly, killed all mites. 

 Swiss beekeeping owes Mr. Frow great gratitude for his discovery 

 which he, in absolute unselfishness, offered the public for use, 

 Acarine disease will soon be no longer a matter for public concern 

 in Switzerland, since every beekeejjer is able to protect his apiary 

 from infection by correct application of this remedy. What remains 

 for us to do in this matter is to get rid of certain disadvantages 

 of the Frow treatment, principally the danger of robbing. 



As far as the success of control is concerned, we can therefore 

 compare acarine disease with American foul brood. On the other 

 hand European foul brood has points of great similarity with 

 Nosema disease, as I have already noted in my remarks relating 

 to seasonal occurrence. Also, as yet an effective control method 

 has not been found for Nosema disease. As with European foul 

 brood, one knows much too little of its nature. We are glad that 

 we have not included Nosema in the animal disease law. Before 

 we can introduce a Nosema law or a Nosema insurance, we must 

 study the disease itself further. With us the Swiss Nosema com- 

 mission has taken up this task. In it the federal veterinary office, 

 the entomological institute in Ziirich, the bee division at Liebefeld, 

 and the beekeepers' societies are represented. I think that our 

 Nosema commission corresponds exactly to your Bee Research 

 Advisory Committee. 



In the Nosema question we have sufficient material for at least 

 a days' discussion. You all know the remarkable phenomenon in 

 which a bee colony which is 100 per cent, infected with Nosema 

 can appear absolutely healthy externally. I shall not try your 

 patience by naming all Nosema theories and should like here only 

 to offer for discussion the theory which we hold at the present time. 

 We believe that Nosema infection alone, in a well-managed 

 colony and under good conditions, cannot cause great damage. 

 The dreaded devastation which has hitherto been ascribed to 



