64 The Isle of Wight Bee Disease. 



ground in front of the hives, frequently mussed together in 

 little clusters, while others remain on the alighting board. If 

 the hives be opened, numbers of sluggish diseased individuals 

 will often be met with inside, clustered together round or near 

 the queen, who is usually the last to die. Diseased bees verj' 

 frequently lose their power of flight altogether, and then crawl 

 about with the extremity of the distended abdomen dragging 

 along the ground ; not infrequently the wings are " out of 

 joint," the hind wings protruding obliquely upwards and 

 above the anterior pair. The distension of the abdomen 

 appears to be due to the inability of the bee to fly. The hind 

 intestine becomes loaded with pollen and other material, 

 which is normally voided when the insect is on the wing. If, 

 however, for any cause it is unable to take its cleansing flight 

 the hind gut remains loaded. In some cases, however, diseased 

 bees show symptoms akin to those of dysenterj^ They dis- 

 charge their excrements over the combs and on the sides, floor, 

 and alighting board of the hive. Many bee-keepers have 

 inforined me that this condition is only present after the 

 winter confinement within the hive. A comb constructed by 

 a diseased stock during the summer does not as a rule reveal 

 any such " dysenteric " symptoms. 



The symptoms enumerated are those most commonly 

 observed among bees infected with the Isle of Wight disease, 

 but other and less important indications may also occur. It 

 must be remembered, however, that no single one of these 

 symptoms can be regarded as diagnostic of the disease. The 

 only invariable feature is the death of large numbers of bees 

 and frequently of the whole stock. The mortality is especially 

 prevalent during wet and cold periods and during the winter 

 season. There is evidence to show that the disease may be less 

 virulent during hot dry seasons, and that epidemics are more 

 likely to break out during periods of cold and wet weather. 

 The coinplaint may often be present when unsuspected, under 

 conditions apparently favourable to the bees rather than to the 

 disease, and only evince its presence by a gradual dwindling of 

 the stock without any apparent cause. It is only when the 

 disease assumes the form of an epidemic that it attracts much 

 notice, and efforts are made to cope with it when the stock is 

 already doomed. 



Cause of the Disease. 



In 190() Drs. Fantham and Porter observed a minute one- 

 celled animal parasite in the digestive system of bees obtained 

 from the Isle of Wight. In 1907 they were again successful 

 in finding this parasite, and in the years 1908-10 they obtained 

 it from bees showing symptoms of the Isle of Wight disease 



