30 BULLETIN "780, U. S. DEPAETMENT OF AGBICULTUKE. 



Table \l.— Experiments to determine the heat required to destroy Nosema apis suspended 



in water} 



' In omitting fractions of degrees the nearest whole number is given. 



From Table VI it will be observed that Nosema apis in a water sus- 

 pension was destroyed ■ in 10 minutlss at a temperature somewhere 

 between 135° F. (57° C.) and 138° F^(59° C.).. 



, NOSEMA APIS SUSPENDED IN HONEY. 



From preliminary experiments it was learned that the amount of 

 heating that is required to destroy Nosema apis suspended in glycerin 

 is approximately equal to that required to destroy it when suspended 

 in water. It was anticipated, therefore, that the minimum amount 

 of heating that would destroy the germ suspended ia honey would 

 approximate that required to destroy it when suspended ia water. 



Experiments were made to determine the approximate thermal 

 death point of Nosema apis when it is suspended in honey. In 

 making the experiments the technique used was similar in the main 

 to that of the preceding group of experiments wherein suspensions in 

 water were heated. In Table VII are summarized the experiments 

 performed, together with the results obtamed. 



Table VII:.^ 



-Experiments to determine the heat required to destroy Nosema dpis suspended 

 m honey. 



: — i 



Date of inoculation. 



Aug. 28, 1915 

 Aug. 27, 1915 

 June 9, 1915. 

 May 21, 1915. 

 June 8, 1915. 

 Aug. 28, 1915 

 June 9, 1915.. 

 June 8, 1915. 

 Mays, 1915.. 

 May 21, 1915. 

 May 21, 1915. 



Temperature 

 employed. 



68 



136 

 138 

 138 

 140 

 142 

 142 

 144 

 146 

 149 

 158 

 176 



Period of 

 heating. 



Minutes. 

 10 

 10 

 10 

 10 

 10 

 10 

 10 

 10 

 10 

 10 

 10 



Kesults of inoculations. 



Nosema infection produced. 



Do. 

 No infection produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



