40 
BULLETIN 780, U. S. DEPARTMENT OE AGRICULTURE. 
The experiments summarized in Table XX show from the results 
recorded that Nosema apis, when suspended in honey and kept at 
room temperature, shielded from the light, remained virulent for 
from 66 to 124 days, that is, from 2 to 4 months. The wide varia- 
tion noted here probably is due very largely to the variation in 
temperature of the honey suspension. 
PERIOD IN DEAD BEES. 
Among the factors tending to destroy Nosema apis within the 
remains of dead bees are drying, putrefaction, and probably fermen- 
tation. The temperature also is to be expected to vary the period 
of resistance. In conducting the experiments, therefore, incubator, 
room, outdoor, and refrigerator temperatures were used. Infected 
bees were killed and kept in these different environments. After 
different intervals suspensions were made in sirup, the crushed 
bodies of from 5 to 10 of the infected bees being used. Colonies 
were inoculated with the suspensions. 
AT INCUBATOR TEMPERATURE. 
Table XXI summarizes the results obtained when inoculations 
were made with suspensions of Nosema-infected material from bodies 
of bees kept at incubator temperature. 
Table XXI. — Resistance of Nosema apis within dead bees at incubator temperature 
(37.5° C). 
Date of inoculation. 
Period 
of 
drying. 
Results of inoculation. 
Apr. 9, 1916. , 
Apr. 12, 1916. 
Apr. 14, 1916. 
June 27, 1916 
July 1,1916., 
May 17, 1916. 
Aug. 4, 1915. 
Oct. 8, 1914.. 
Aug. 8, 1915. 
Aug. 17, 1915 
Oct. 19, 1915. 
Aug. 23, 1915 
Aug. 6, 1914. 
Nov. 2, 1914. 
Days. 
Nosema infection produced. 
Do. 
Do. 
No infection produced. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
By the results recorded in the experiments summarized in Table 
XXI, it was shown that Nosema apis in the bodies of dead bees 
kept at incubator temperature ceased to be virulent in less than one \ 
week. 
AT ROOM TEMPERATURE. 
In Table XXII are summarized the experiments in which dead 
bees, kept at room temperature, furnished the Nosema-infected 
material for the suspensions used in the inoculations. 
