20 BULLETIliT 780, U. S. DEPARTMENT OF AGRICULTURE. 



Table V. — Summary of results from a study of Nosema infection in an apiary. 



\ 



Mq.rch. 



April. 



M«y. 



June. 



July. 







-d 







-a 







-d 







■d 







-d 





Year. 



1 



S 





1 



1 





73 







"3 



■^ 





■d 



s 



-2 

 









i 



3 



a 



^ 



.■a 



fl 



1 



1 



n 



g 



3 



rl 



HI 







03 



fl 













D 



s 



0) 



S 





§ 





® 



^ 



i 







m 



'A 



Ph 



w 



J< 



PM 



w 



JZi 



fL, 



pq 



12; 



P4 



cq 



!z; 



(1, 



1912 









240 



72 



30 



410 



96 



23 



130 



19 



15 



130 



21 



16 



1913 



270 



28 



10 









50 



1,050 



200 



7 

 166 



ifi' 



220 

 700 



8 

 60 



4 

 9 



260 

 "'40 



23 

 2 



9 



1914 









1 



1915 



50 



6 



12 



280 



24 



9 



16 



8 





























Total 



320 



34 



11 



520 



96 



18 



1,910 



285 



17 



1,050 



87 



8 



630 



46 



7 











August. 



September. 



October 







■d 





















"§ 



-2 

























§ 



a 









-d 







■d 







■d 





•3 



y 





Year. 



■a 



1 





1 



1 





1 



1 







a 







1 



•a 





■| 



■g 





1 



•a 







s 



s 







s 



d 



+i 



M 



fl 



+» 



X 



fl 



d 



,0 



!? 



a 





V 







09 





(S 



S 













§ 



!P 



s. 



§ 



h 



S 





Ui 



1 



03 

 







w 



!zi 



S 



m 



^ 



^ 



W 



^ 



PM 



Eh 



H 



P^ 



1912 



60 

 240 



14 

 11 





170 

 170 

 220 



14 

 43 



8 

 25 









1,140 



1,270 



2,210 



630 



236 



228 



121 



46 



20 



1913 



5 



60 



1 





10 



1914 



10 





















9 

























Total 



300 



25 



8 



560 



57 



10 



60 



1 





5,150 



631 



12 















1 













1 





1 





From Table V it will be observed that the number of infected 

 bees found at different periods of the year varied considerably. 

 April and May furnished the highest percentage, being 18 and 17 

 per cent respectively. In March, June, July, August, and Sep- 

 tember the number of Nosema-infected bees among those examined 

 was 11, 8, 7, 5, and 10 per cent respectively. Out of 5,150 bees 

 taken from the apiary from April, 1912, to June, 1915, and exam- 

 ined, 631 (12 per cent) were Nosema infected.^ 



Laidlow (1911) reports that out of somewhat more than 1,500 

 bees received from various parts of Australia, 17 per cent were 

 found to be Nosema infected. 



From an examination of the foregoing tables it is seen that Nosema 

 infection was found to be present in practically every colony of the 

 apiary. Had further examinations been made of the few colonies 

 in which Nosema apis was not found, one could well expect, from 

 what is known of the disease, that these, too, would have revealed 

 the presence of the infection. It is seen also that the infection 

 persisted throughout all seasons of the year, and that it was heaviest 



1 While this three-year study was being made the apiary served for other work. It is hkely that the 

 attending manipulations were accompanied from time to time by a certain amount of robbing. From the 

 nature of the disease, however, it is not believed that this fact affected materially the results obtained. 



