8 Department Circular 287, U. S. Dept. of Agriculture. 



apiaries and of all bees over considerable areas to relatively minor 

 losses. In certain cases (44) to be discussed later (p. 18), the results 

 are chiefly a reduction of the honey crop through the death of an 

 abnormal numher of field workers. It is quite natural that early 

 reports from Great Britain should emphasize the severe cases, 

 especially during the period when the cause of the disease was not 

 yet known. There are evidently chronic cases of the Isle of Wight 

 disease in England and Switzerland, as is clear from a reading of the 

 literature. There is also reason to suspect that such cases are com- 

 mon in France, because of several statements that the disease is less 

 destructive there than in England, these writers evidently having 

 in mind only the reports of severe attacks in England. There can 

 be no question, after reading the reports from Great Britain for a 

 number of years, that the total losses to beekeeping have been heavy 

 and that in many cases beekeepers have lost all their bees from this 

 disease. Some competent beekeepers claim that the damage in Eng- 

 land is not now so great as formerly, but such claims are always to 

 be expected as soon as a disease begins to come under control through 

 more knowledge, and there is no definite reason to believe that the 

 Isle of Wight disease is becoming less capable of doing damage. 



An interesting paper has appeared by Anderson (61), oi the North 

 of Scotland College of Agriculture, in which he discusses especially 

 the apparently decreased virulence of the Isle of Wight disease in 

 Great Britain in recent years, as well as the various methods which 

 have been employed for its control. The reason for the assumed 

 decrease in the damage from the disease is not clear, but it is stated 

 that on entering new districts the disease is as serious as ever. 



ERRORS FROM DOUBTFUL DIAGNOSIS. 



A curious difficulty which one encounters in attempting to esti- 

 mate the damage done in Great Britain by the Isle of Wight disease 

 and the efficacy of suggested remedies arises from diagnoses by 

 incompetent persons, who, even before the determination of the cause 

 of the disease, published diagnoses from dead bees submitted for 

 examination. Some British beekeepers have relied on these diag- 

 noses and have then used them as a basis for experiments on treat- 

 ments, and it is thus impossible to determine the value of much of this 

 work. Many American beekeepers have discounted the reports of 

 heavy losses in Great Britain from the Isle of Wight disease chiefly 

 because of their lack of confidence in the diagnoses and, in fact, many 

 were for this reason led into a sense of false security regarding the 

 disease. Even since the discovery of the cause of the disease, such 

 ill-advised practices seem to continue, in spite of the repeated warn- 

 ings of Eennie. 



THE UNITED STATES. 



Immediately following the publication of the first paper (46) on 

 this subject a conference called by the chairman of a committee ap- 

 pointed by the apiculture section of the Association of Economic 

 Entomologists was held at the bee culture laboratory on March 9, 

 1922, to consider the desirability of taking steps to prevent the intro- 



