NOSEMA-DISEASE. 



33 



It is learned from the results recorded in Table XI that Nosema 

 apis drying at refrigerator temperature remained virulent for seven 

 months but that no disease was produced following inoculation with 

 the material after seven and one-half months drying. 



From the results obtained in the experiments relative to the resist- 

 ance of Nosema apis to drying, given in Tables VIII-XI, it will be 

 observed that the period the parasite remained alive, or at least 

 virulent, varied, depending upon the environment of the germ. The 

 shortest period for the destruction of spores was obtained under 

 incubator conditions, while the longest period occurred under refrig- 

 erator conditions. The death probably was not due to the drying 

 alone but to a combination of factors of which drying was an impor- 

 tant one. 



RESISTANCE OF NOSEMA APIS TO FERMENTATION. 



Experiments have been made to obtain data relative to the resist- 

 ance of Nosema apis to fermentative processes. In conducting the 

 experiments suspensions of the crushed stomachs from Nosema- 

 infected bees were made in a 10 per cent sugar (saccharose) solution 

 and in a 20 per cent honey solution. These solutions were distributed 

 in test tubes. Each tube contained infectious material equal to that 

 present in the stomachs of from 5 to 10 infected bees. To each sus- 

 pension was added a bit of soil to inoculate it further. Suspensions 

 were allowed to ferment at incubator, room, outdoor, and refrigerator 

 temperatures, respectively. At intervals reckoned in days the fer- 

 menting suspension from a single tube was transferred to about one- 

 haK pint of sugar sirup and fed to a colony free from the infection. 

 The results were then noted. 



FERMENTATION AT INCUBATOR TEMPERATURE. 



In Table XII are summarized some of the results that were obtained 

 when a suspension of Nosema apis in a 20 per cent aqueous solution 

 of honey was allowed to ferment at incubator temperature. 



Table XII. — Resistance of Nosema apis to fermentation in a honey solution. 



Date of inoculation. 



Results of inoculation. 



July 25, 1916. 

 July 26, 1916. 

 July 27, 1916. 

 July 28, 1915. 

 July 12, 1915. 

 July 15, 1916. 

 July 17, 1916 



Nosema infection produced. 



Do. 

 No infection produced. 



Do. 



Do. 



Do. 



Do. 



