NOSEMA-DISEASE. 



39 



In the experiments it was found that Nosema apis was destroyed 

 in all instances in which the temperature of the honey reached or 

 exceeded 140° F. (60° C), a temperature at which the germ is killed 

 by heat (p. 30). Sufficient data, therefore, have not been obtained 

 to warrant a definite conclusion regarding the time required for the 



Fig. 7.— Petri dish. The top half is slightly raised. Those 

 used here are 4 inches in diameter. 



direct sunlight to destroy Nosema apis suspended in honey. The 

 results obtained from the experiments made in which aqueous sus- 

 pensions were exposed to the sun give some idea as to the probable 

 approximate time which would be required. 



PERIOD NOSEMA APIS REMAINS VIRULENT. 



PERIOD IN HONEY. 



In experiments made to determine the length of time Nosema apis 

 remains virulent in honey a suspension of the parasite in honey was 

 distributed in flasks, about one-haK pint being poured into each flask." 

 These were placed at room temperature and shielded from the light. 

 After different intervals colonies were inoculated, the suspension 

 from a single flask being used. The results obtained are included 

 in Table XX. 



Table XX. — Period Nosema apis remains virulent in honey. 



Date of inoculation. 



Period in honey. 



Mbnihs. 



Days. 



1 







1 



18 



2 







3 



10 



3 



27 



2 



6 



2 



15 



2 



25 



3 



5 



3 



17 



3 



20 



3 



21 



4 



4 



5 







7 



17 



7 



19 



9 



7 



9 



19 



12 







Results of inoculation. 



Oct. 20, 1914... 

 Feb. 4, 1915.... 

 Feb. 24, 1915... 

 Feb. 4, 1915.... 

 Jan. 16, 1915... 

 July 14, 1915,.. 

 July 23, 1915... 

 Oct. 21, 1915... 

 June 11, 1915.. 

 Sept. 3, 1915... 

 June 24, 1915... 

 Oct. 21, 1915... 

 July 24, 1916... 

 Aug. 14, 1913.. 

 Mayl, 1915.... 

 June 9, 1914... 

 Apr. 27, 1915... 

 May 5, 1914.... 

 July 26, 1916... 



Nosema infection produced. 



Do. 



Do. 



Do. 



Do. 

 No infection produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



