30 
BULLETIN 780, U. ,S. DEPARTMENT OF AGRICULTURE. 
Table VI. — Experiments to determine the heat required to destroy Nosema apis suspended 
in water. 1 
Date of inoculation. 
Temperature 
Period of 
employed. 
heating. 
°C. 
°F. 
Minutes. 
50 
122 
20 
55 
131 
10 
56 
133 
10 
56 
133 
10 
58 
136 
10 
57 
135 
10 
58 
136 
10 
58 
136 
10 
59 
138 
10 
60 
140 
• 10 
60 
140 
10 
60 
140 
10 
61 
142 
10 
65 
149 
10 
65 
149 
10 
80 
176 
20 
100 
212 
5 
Results of inoculations. 
Jan. 31, 1913. 
Jan. 8, 1913.. 
Oct. 4, 1913.. 
Oct. 15, 1913. 
May 21, 1915. 
Oct. 15, 1913. 
Feb. 8, 1913. 
Oct. 4, 1913.. 
Aug. 28, 1915 
Nov. 11, 1912 
Nov. 20, 1912 
May 21, 1915. 
Aug. 28, 1915 
Nov. 12, 1913 
Jan. 8, 1913.. 
Oct. 29, 1912. 
Nov. 12, 1912 
Nosema infection produced. 
Do. 
Do. 
Do. 
Do. 
No infection produced. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
1 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 minutes 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 in honey would 
approximate that required to destroy it when suspended in 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 obtained. 
Table VII. 
-Experiments to determine the heat required to destroy Nosema apis suspended 
in honey. 
Date of inoculation. 
Temperature 
employed. 
Period of 
heating. 
Results of inoculations. 
Aug. 28, 1915 
°C. 
58 
59 
59 
60 
61 
61 
62 
63 
65 
70 
80 
°F. 
136 
138 
138 
140 
142 
142 
144 
145 
149 
158 
176 
Minutes. 
10 
10 
10 
10 
10 
10 
10 
10 
10 
10 
10 
Nosema infection produced. 
Aug. 27, 1915 
Do. 
June 9, 1915 
No infection produced. 
May 21, 1915 
Do. 
June 8, 1915 
Do. 
Aug. 28, 1915 
Do. 
June 9, 1915 
Do. 
June 8, 1915 
Do. 
May 5, 1915 
May 21, 1915 
May 21, 1915 
Do. 
Do. 
Do. 
