NOSEMA-DISEASE. 
43 
From the results recorded in Table XXV it is seen that when the 
dead Nosema-inf ected bees were allowed to remain on the soil exposed 
to outdoor conditions Nosema apis was virulent at the end of 44 days, 
but the germ had lost its virulence before 71 days. Results of 
experiments having the nature of those referred to in this table 
naturally depend largely upon the climatic conditions which prevail. 
It was observed that insects, ants especially, fed upon the dead 
bees lying on the ground. In this way they removed much of the 
material containing the parasites. This fact must be borne in mind 
in a consideration of the length of time that bees dead of Nosema 
disease and lying on the soil might serve as a possible source of 
infection. 
The five foregoing groups of experiments relative to the period 
during which Nosema apis remains virulent in the bodies of dead 
infected bees show that the period varies with the environment under 
which the bees are kept, the temperature being an important factor 
in causing the variation. It is interesting to note that under fairly 
favorable conditions for its preservation Nosema apis remains 
virulent within the bodies of dead infected bees only three months, 
while under less favorable conditions its destruction occurs in a much 
shorter period. 
INFECTIOUSNESS OF BROOD-COMBS FROM NOSEMA-INFECTED 
COLONIES. 
Experiments have been made for the purpose of obtaining data 
relative to the likelihood of the transmission of Nosema disease from 
colony to colony through the medium of brood-combs. Brood- 
combs on which colonies had died of the disease and others taken 
from colonies heavily infected with Nosema apis through experi- 
mental inoculation were inserted into healthy colonies after different 
periods of time had elapsed following their removal. Table XXVI 
gives a summary of experiments made and the results obtained. 
Table XXVI. — Results from insertion of brood-combs from Nosema-inf ected colonies 
into healthy ones. 
Date combs were inserted. 
Period combs 
were stored. 
Number 
of combs 
inserted. 
Results of inoculation. 
Apr. 20, 1915. 
Do 
Apr. 26, 1915. 
July 3, 1915.. 
May 19, 1916. 
Apr. 26, 1915. 
Do 
Apr. 24, 1915. 
June 18, 1914. 
June 29, 1914. 
Apr. 24, 1915. 
May 1,1915.. 
Aug. 22, 1914. 
May 19, 1916. 
Inserted im- 
mediately. 
....do 
....do 
....do 
I month.. 
do... 
1 month.. 
2 months. 
do... 
3 months. 
do... 
4 months. 
6 months. 
No Nosema infection pro- 
duced. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
