40 



Nusenia disease is an infectious disorder of adult bees and 

 attacks both tlie queen and drone as well as the worker but 

 not the brood. The chief sources of infection are the drinking 

 places visited by bees; stagnant pools should not be allowed, 

 there being less danger in running water. 



The resistance* of the disease is as follows: — • 



1. Nosema Apis suspended in water is destroyed by heating 

 for 10 minutes at about 136° F. (38° C). 



2. Suspended in honey, Nosema Apis is destroyed by heat- 

 ing at about 138° P. (69° 0.). 



3. Nosema Apis, drying at room and outdoor temperatures- 

 respectively, remains vinilent for about 2 months ; at incubator 

 temperature about 3 weeks and in a refrigerator about 7| 

 months. 



4. Nosema Apis suspended in water is destroyed by exposure 

 to the sun's rays iro^m 37 to 51 hours. (Hence it Is advisable 

 not only to control the water supply to the bees, but also fo 

 have it regularly exposed to the sun's rays; at the same time 

 a board should be so arranged above that the bees cannot drop 

 (heir faeces into the water. A glass water fountain is superior 

 to one of zinc, or to a metal or wooden pail or tub.) 



5. Nosema Apis remains virulent in honey for from 2 to 4 

 months. 



6. Nosema Apis in the bodies of dead bees lying on the 

 soil ceases to be virulent in from 44 to 71 days. 



7. Nosem,a Apis is readily destroyed by carbolic acid, a 

 1 per cent, aqueous solution destroying it in less than ten 

 minutes. 



Remedial and Preventive Measures. — Mo certain remedy 

 has been discovered for Microsporidiosis, most cises of so-- 

 called cures that have been investigated having been based 

 on faulty observations. A few recommendations, however, 

 can be given for preventing the spread of disease, and for 

 mitigating its severity when it appears. 



1. Cleanliness. — Great care should be taken to keep the 

 hives and the surroundings of the apiary clean. Cleanliness 

 will not in itself secure immunity from disease, but dirty or 

 damp surroundings lower the vitality of ^he bees and render 

 them more liable to attack. All bee-keepers who can give 

 the necessary time to their attention should adopt British 

 standard frames and moveable comb hives, but those only 

 able to use skep hives should renew them every two or three 

 years. 



After an outbreak of. disease the interior of all moveable 

 comb hives should be charred with a painter's lamp as advised 

 in the text books. They should not be used again for several 

 weeks.. All skep's, quilts, old combs, and dead bees should 



* White, G. F., Nosema Disease, U.S. Depf. of Agriculture Bull. 780- 

 1919. 



