IvTOSEMA-DISEASE. 53 



without the hive." They beheved that the condition had been 

 endemic in parts of England for many years, and shared with 

 Graham-Smith the behef that a large amomit of the losses among 

 adillt bees ascribed to it is due to Nosema infection. 



From the facts at hand it is not possible to state whether the Isle 

 of Wight disease and Nosema-disease are one and the same disorder. 

 Studies made on the Isle of Wight disease by English workers will 

 most likely result in revealing further valuable facts concerning it 

 (Anderson and Rennie, 1916). The writer examined one sample of 

 adult bees from England taken from a colony suffering from Isle of 

 Wight disease. No spores of Nosema ajns were found in the sample. 

 The results of the examination naturally prove nothing regarding 

 the disease. 



For the present the American beekeeper should bear in mind that 

 when Nosema-disease is given as the diagnosis, a condition having 

 the destructiveness described for the Isle of Wight disease is not 

 meant. 



OTHER DISEASES OF ADULT BEES. 



It is quite probable that other diseases of adult bees than those 

 referred to here exist. If so, they have not yet been sufficiently 

 studied to make their recognition possible, at least by laboratory 

 methods. Such disorders could be differentiated from Nosema- 

 disease by the absence in them of Nosema apis. As Nosema infection 

 is very widely distributed among bees, the fact must always be 

 borne in mind that Nosema infection may occur in a colony together 

 with other bee diseases and be of secondary importance. This 

 caution should never be overlooked. 



PROGNOSIS IN NOSEMA-DISEASE. 



The prognosis in Nosema-disease varies markedly and is dependent 

 upon the conditions present. Of these conditions the percentage of 

 Nosema-infected bees in the colony, the strength of the colony, the 

 season of the year, and the environment of the apiary are among the 

 more important factors which determine the outcome of the disease. 



The percentage of Nosema-infected bees in the colony may be very 

 small, much less than 1 per cent, or it may be very large, reaching 

 practically 100 per cent. Between these hmits aU degrees of infec- 

 tion are encountered, the prognosis in each instance being different. 



As a rule colonies which in the spring of the year show less than 

 10 per cent of Nosema-infected bees gain in strength and the losses 

 are not detected. This is often true also in cases where the infection 

 is somewhat greater than 10 per cent. When the number of infected 

 bees approaches 50 per cent the colonies become noticeably weakened 

 and in many instances death takes place. When more than 50 per 



