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(a) Isle of Wight Disease 



This disease has been a very serious source of loss to British beekeep- 

 ers. It is caused by a minute mite which crawls into the bee's spiracles 

 choking off its supply of air and possibly secreting a toxine which 

 paralyzes the wing or flight muscles. Most adult bee diseases have quite 

 similar symptoms, making diagnosis from external characteristics diffi- 

 cult. 



The following is taken from leaflet No. 253, issued by the Board of 

 Agriculture and Fisheries, 4 Whitehall Place, London, England: 



Sijinptoms: 



1. The first symptom noticed is a disinclination to work. They fly 

 about aimlessly and do not gather stores. 



2. Later they lose their powers of flight and are unable to travel 

 more than a few yards without alighting. 



3. As the disease progresses, the bees are unable to fly more than a 

 few feet, when they drop and crawl. They may be seen crawling up 

 grass stems or other upright objects, but they soon fall down and die. 

 Towards night some may be seen gathered in groups, but they usually die 

 before morning. 



4. The abdomen is often swollen. 



5. The wings often appear disconnected. Sometimes the legs seem 

 affected, and the bees stagger in their attempt to walk. 



6. Finally the whole colony of workers is found clustered in front 

 of the hive, except a few which are found crowded around the queen. 



7. The queen and the brood are not attacked, though "chilled brood" 

 often appears subsequently, owing to there being insufficient bees to keep 

 the hive warm. 



(b) NosEMA Disease 



This disease although fairly widespread is mild in character. It is 

 caused by a protozoan or one celled parasite, Nosema apis, which infests 

 the alimentary canal of adult bees. Bees can be infested with Nosema 

 spores without showing any marked symptoms of disease, and apparently 

 with little effect on their ability to carry on. Death may result from 

 infection and in the case of excessive infection bring about a weakening 

 effect on the colony through the shortening of the life of the individuals. 

 Bees are often observed crawling around outside the hive or climbing up 

 blades of grass. Requeening and strengthening by giving additional 

 capped brood usually brings relief. Cases of this disease have been 

 known in Canada. 



(c) Dysentery 



Dysentery is more properly a disorder than a disease of adult bees. 

 Bees are only able to void faeces while in flight. During the winter 

 waste matter accumulates in the lower intestine. If the food is of good 

 quality and the bees are not conflned to the hives for too long a period, 

 they will be healthy in the spring. If the food contains considerable 

 indigestible material and the bees are unable to fly they often die in great 



