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ISLE OF WIGHT DISEASE IN HIVE BEES. 



John Rennie, D.Sc, University of Aberdeen, and 

 Elsie J. Harvey, Research Assistant. 



[Reprinted from " The Scottish Journal of Agriculture" 

 Vol. II., No. 2, April 1919.] 



In a former paper issued under the present investigation ^ tht 

 failure to produce Isle of Wight disease in hive bees within a 

 working season by means of direct contact with frames and hives 

 and by feeding upon stores of bees suffering from this disease, was 

 established in a limited number of cases. 



Further experiments and observations of a like kind have 

 been continued, and in six other instances the result within the time 

 specified was tiie same, i.e. disease did not develop amongst the 

 bees which fed upon the stores and lived upon the frames of sick 

 bees during the whole of the experimental period, which in each 

 case extended over the whole of the working season. It would 

 certainly appear that normally the disease is not readily communi- 

 cated by such means. 



In addition to the foregoing we now desire to record further 

 experiments in which sick worker bees, brood and queens from 

 diseased stocks have been separately utilised.* 



Experiments in Infection by means of Frames, Stores, and 

 Sick Bees. — Summer Experiments. — No. i. A stock, whose earlier 

 history is given in the communication referred to above, p. 56, 

 wintered (1915-16) successfully. In March flying had commenced 

 and pollen was being taken in. During this month an adjacent stock, 

 a swarm of the previous summer, developed very definite signs 

 of Isle of Wight disease, and large numbers of bees crawled when ' 

 the weather admitted of their coming out. Bees of both stocks 

 were repeatedly examined for Nosenta apis, and no stage of the 

 parasite was found. 



On the nth April the queen of the diseased stock was removed 

 and the two were united. The union was accomplished with 

 comparatively slight mortality. During May the weather was good 

 and the disease symptoms disappeared. The stock was seen 

 working on every fine day. It now appeared prosperous, and there 

 were large numbers of eggs, larvae, young and old workers and a 

 good supply of stores. 



' Proc. Roy. Phys. Soc. Edin., 1916. 



' These experiments have been carried out concurrently with an investigation 

 upon the relation of the parasite Nosema apis to Isle of Wight disease. This 

 is in course of publication in a separate paper. We conclude that the causal 

 organism of Isle of Wight disease has not yet been found. 



The researches have been conducted with the aid of Grants provided by the 

 Development Commissioners through the Board of Agriculture for Scotland. 



(6.) 50. 6/19. J.s.&Cc.Ltd. 



