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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
Just what relation the parasite Nosema apis may bear to this trouble 
is not yet proven, but the symptoms in bees affected by this trouble 
are strikingly similar to the described symptoms of Isle of Wight disease 
which has been thought to be caused by this parasite. 
Imms 1 says “this parasite affects the digestive system and there is 
an enlargement of the posterior parts of the intestine particularly the 
colon and rectum” which appears to support the theory of defective 
digestion. He further says “beekeepers claim to prevent the occur¬ 
rence of this disease by feeding.” This further supports the theory. 
The results of the studies of Nosema apis by Fantham and Porter 2 
appear to coincide with the conditions accompanying this trouble. 
They state that “the virulence of the parasite ( Nosema apis ) appeared 
to vary in bees at different times of the year and in different locations.” 
This possibly accounts for the manner in which this trouble appears 
at widely scattered points. 
Fantham and Porter 3 have found Nosema in greatest numbers in the 
chyle stomach and in a lesser degree in the small intestines. The 
spore stage is the only stage they have proven capable of infecting new 
hosts. 
The observations and experiments by Anderson and Rennie 4 ap¬ 
parently fail to connect Nosema apis in any causal relation with Isle 
of Wight disease. They were unable to convey the disease by contact 
with contaminated hives or combs or by feeding contaminated stores. 
They found spores of Nosema apis in bees showing no symptoms of 
disease and the examination of many bees showing the disease re¬ 
vealed no trace of Nosema apis. Their observations revealed, usually, 
only a small per cent of colonies in an apiary affected by disease and 
aside from one colony of what they called “American goldens,” the 
disease affected one race as readily as another. 
In the work at the Bee Culture Laboratory at Washington Nosema 
apis has been found in both sick and apparently healthy bees. 
The observations of the various persons mentioned seems to leave con¬ 
siderable doubt as to Nosema apis being the cause of the disorder ob¬ 
served. The presence of Nosema in bees apparently healthy, might 
be explained by the work of Fantham and Porter who claim that some 
1 Imms, A. D. (Journ. Bd. Agric., London, 14 [1907], No. 3, pp. 129-140, fig. 3.) 
2 Fantham, H. B., and Porter, Annie. (Proc. Zool. Soc., London, 1911, III, pp. 
625-626.) 
3 Fantham, H. B., and Porter, Annie, 1914, “Some Minute Animal Parasites,” 
London. 
4 Anderson, J., and Rennie, J., 1915-1916, “Observations and Experiments Bear¬ 
ing on ‘Isle of Wight’ Disease in Hive Bees.” Royal Phys. Soc. of Edinburgh, 
vol. XX, part I. 
