18 
BULLETIN 780, U. S. DEPARTMENT OF AGRICULTURE. 
The percentage of infected bees found during the spring and sum- 
mer remained quite constant, increasing unexpectedly in September. 
The reason for the increase can not be assigned at present. 
Out of the 25 colonies in the apiary in March, 1913, 1 (No. 12) died. 
As this colony contained a high percentage of Nosema-inf ected bees, 
and as it dwindled until it disappeared, it may be assumed that 
Nosema-disease was the immediate cause of its death. As in the 
preceding year all of the colonies that liyed behaved much as do 
uninfected ones. 
In this year another experiment was begun in the apiary. This 
one is described as experiment No. 2 (p. 25). 
Studies similar to these made in 1912 and 1913 were continued 
throughout 1914 and until June, 1915. While in the main the col- 
onies of the apiary were those of the previous years, naturally there 
had been some changes. The results obtained are summarized in 
Table IV. 
Table IV. — Results obtained from May, 1914, to June, 1915, from a study of Nosema 
infection in an apiary. 
1914 
1915 
Colony No. 
May. 
June. 
July. 
Sep- 
tem- 
ber. 
No- 
vem- 
ber. 
March. 
April. 
May. 
2 
8 
12 15 
27 
5 
8 
18 
15 
10 
23 
5 
2 
8 
25 
7 26 
1 
2 
0« 
2° 
1«> 
1« 
0* 
0° 
1« 
0° 
1 
Op 
1* 
2° 
1« 
2« 
2" 
0° 
0« 
1" 
1» 
0* 
0* 
3« 
4« 
2« 
0« 
7« 
1« 
1p 
2p 
1* 
IP 
IP 
0p 
2p 
Op 
Op 
2° 
1p 
2* 
1p 
2p 
4p 
1p 
Op 
1p 
3p 
2p 
2p 
...J Op 
...J 1p 
.».. 3p 
.... 1p 
.... 1p 
.... 1p 
Op 
Ip 
lh 
2* 
2h 
2h 
2h 
2h 
lh 
4h 
lh 
lh 
0e 
2^ 
lb 
4h 
3^ 
2^ 
lh 
2h 
3h 
lh 
3»» 
2h 
Op 
Op 
Ip 
Op 
0b 
Op 
lh 
0° 
Oh 
Op 
0^ 
le 
2h 
Oh 
Oh 
lh 
2h 
lh 
lh 
2h 
OP 
Oh 
IP 
5p 
"ip' 
2p 
"ip" 
ip 
3p 
2p 
3p 
lh 
2p 
Ip 
3p 
3p 
2h 
Op 
Ip 
2p 
Op 
Op 
Ip 
Op 
Ip 
Op 
Ip 
Op 
Ip 
Op 
Op 
Op 
Op 
Op 
Op 
Ip 
Op 
Op 
Op 
Ip 
Ip 
Ip 
Op 
Ip 
Op 
3p 
Ip 
Op 
Op 
Op 
" Op" 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Ip 
Ip 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
Op 
0e 
0« 
Oe 
Oe 
Oe 
Oe 
Oe 
Oe 
Op 
Op Oh 
3 
Oe 
Oe 
5 
6 
0« 
Oe 
Op 
Ip , Oh 
0« 
Oe 
Oe 
Oe 
::::::;: 
g 
2p 
Op 
2" 
Op 
2* 
9v 
5 e 
Oe 
D 
9 
10 
11 
14 
15 
16 
1 2p 
.:.. ip 
.... ip 
.... ip 
.... 2p 
np 
Oe 
Oe 
5e 
Oe 
Oe 
Oe 
17 
Op 
le 
Oe 
"15" 
Op 
Op 
Ip 
ip 
Oh 
18 
19 
Oh 
Op 
Op 
Oh 
20 
Oh 
21 
Oh 
22 
2p 
2p 
2p 
3p 
Op 
Op 
4p 
Ip 
"7" 
Op 
Op 
Op 
Oe 
S 
t 
u 
V 
w 
X 
y 
z 
Oe 
Oe 
6e 
Oe 
Oe 
Oe 
Oe 
Oe 
Oe 
Op 
2e 
Oe 
"36" 
"50" 
4p 
2p 
2p 
5« 
3p 
Op 
Ip 
Oe 
Oe 
"66" 
Oe 
"68" 
3h 
6^ 
0p 
Ip 
Oh 
Op 
Op 
Op 
"73" 
"82" 
9e 
1« 
9p 
3p 
le 
0« 
Explanation of Table TV.— The colonies reported in Table IV for 1914 do not bear the same numbers that 
were assigned to them for 1913 in Table III except those designated by numbers in quotation marks. The 
first 9 colonies reported in the table for 1915 bear the same numbers they did in 1914. The identity of col- 
onies numbered by letters "s" to "z" inclusive, had been lost through changes made in the apiary. 
