18 



BULLETIN 180, TJ. S. DEPAETMEISTT OF AGKICULTURE. 



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-infected 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 lived 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 



11 



le 

 lo 

 0" 

 0» 

 1« 



0« 



1 



Op 



le 



2" 

 1" 

 2» 

 2« 

 0« 

 0« 

 1' 

 1» 

 0» 

 0" 

 3« 

 4. 



2« 

 0« 

 7« 

 1« 



Ip 

 2p 

 1" 

 Ip 

 Ip 

 Op 

 2P 

 Op 

 Op 

 2= 

 iP 

 2b 

 IP 

 2p 

 4p 

 ip 

 Op 

 iP 

 3p 

 2p 

 2P 



"2p' 



Op 

 Ip 

 3p 

 Ip 

 IP 

 Ip 

 Op 



'6p" 



2e 



Op 

 2« 

 2P 

 2P 

 Ip 

 Ip 

 Ip 

 2p 

 Op 

 2P 

 2p 

 2p 

 3p 

 Op 

 Op 

 4p 

 Ip 



Ip 



Ih 



2h 

 2h 



2h 

 2h 



2h 



Ih 



4h 



Ih 

 Ih 

 = 

 2h 

 Ih 



4h 



3h 

 2h 

 Ih 

 2h 

 3h 

 Ih 

 3h 

 2h 



Op 

 Op 

 Ip 

 Op 

 Oh 

 Op 



Ih 



0" 

 Oh 

 Op 

 Oh 



le 

 2h 

 Oh 



Oh 

 Ih 

 2h 

 Ih 

 Ih 

 2h 



Op 



Oh 



IP 



5p 



Ip 

 2p 



Ip 

 Ip 

 3p 

 2p 

 3p 



Ih 



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 

 0= 

 0» 

 0« 



Oe 



0" 

 0= 





0= 



Oe 



Op 



Op 



Oh 



2 





3 















4 



Ob 



Oe 















5 





Ob 



Ob 



Op 



Ip 



nh 



6 





7 



Oe 

 Oe 



O" 

 0« 















8 





5b 



Ob 



D 







9 







10 



















11 



















14 



















15 



















16 













Ob 

 Ob 



5b 



Ob 

 Ob 

 Ob 









17 



Op 









le 

 Ob 



i)" 

 Op 

 Op 

 Ip 



Ip 



Oh 



18... . 











19 











Oh 

 Op 

 Op 



Oh 



20 













Oh 



21 













Oh 



22 

















"7" . 



Op 

 Op 

 Op 





Oe 





s 

 t 

 u 



V 



w 



X 



y 



z 





Qb 

 Ob 

 6a 

 Ob 

 Ob 

 Ob 

 Ob 

 Oe 



Ob 



Op 

 2b 



Ob 







"36" 







"50" 



4p 

 2P 

 2P 

 S« 

 3p 





Op 







Ip 



Oe 



Ob 



"66" 







Ob 



"68" 



3h 

 6h 



Op 

 iP 

 Oh 



Op 

 Op 

 Op 











"73" 















"82" 









9b 



le 



9p 

 3p 



1b 











Oe 



Explanation of Table IV. — 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 lette,rs "s" to " z," inclusive, had been lost through changes made in the apiary. 



