NOSEMA-DISEASE. 19 



Table IV shows that out of 1,050 bees examined during May, 



1914, 166 (16 per cent) were Nosema infected. 



In June, out of 700 bees examined 60 (9 per cent) were found 

 infected. 



In July, out of 240 bees examined 2 (1 per cent) were infected. 



In September, 220 bees were examined and no Nosema-infected 

 one was found. 



In November, 60 bees were examined and none was found 

 infected. 



Out of 2,270 bees examined during the summer of 1914, 218 (10 

 per cent) were found infected. 



It will be noted that during the early months of the active bee 

 season of 1914 there was a higher percentage of Nosema-infected 

 bees in the apiary than during a similar period of 1913. 



Two colonies were so weak in May that they were disposed of. 

 In one of these at least (No. 13) the weakness was most probably 

 due to Nosema infection. 



During the first week in July the apiary was moved to a new loca- 

 tion. It is interesting to note that the amount of Nosema infection 

 after removal was reduced to practically nothing. This is not defi- 

 nitely accounted for by the results obtained by these investigations.^ 



Examinations were rriade of a portion of the apiary in 1915. In 

 March, out of 50 bees taken from 5 colonies, 6 (12 per cent) were 

 found to be Nosema infected. 



In April, out of 280 bees taken from 17 colonies 24 (9 per cent) 

 were found infected. 



In May, out of 200 bees taken from 10 colonies 16 (8 per cent) 

 were infected. 



Out of 530 bees examined from the apiary during the spring of 



1915, 46 (9 per cent) infected ones were found. 



Among the colonies that were examined during the spring of 

 1915 two (Nos. 8 and 18) died by the end of April. Both of these 

 contained a rather high percentage of Nosema-infected bees. Two 

 others containing an equal or greater number of infected bees lived 

 throughout May and had recovered apparently by June. In case 

 of these 4 colonies it can properly be said that the two colonies that 

 died died of Nosema disease, whereas the two that lived recovered 

 from it. 



In Table V is given a summary of the results obtained in the study 

 of the apiary from April, 1912, to June, 1915. 



1 Tliat the immediate environment of the apiary determines, to some extent, the presence or absence of 

 Nosema-disease and its transmission seems quite likely. In searching for the cause for such a difference 

 the water supply of the bees, if near by, must not be overlooked (p. 46). In this connection, it may be 

 pointed out that in the experimental apiary (PI. IV) Nosema infection at no time exceeded 1 per cent, 

 excepting naturally in inoculated colonies, although the source from which these colonies were obtained 

 had been largely the apiary which, it will be seen from Tables II and III, showed Nosema infection in from 

 10 to 20 per cent of the bees. Here there was no slowly moving body of water used by the bees as the source 

 of their water supply. 



