ISO 



stock distinctly reduced in numbers. During August in fine 

 weather crawling s\mptoms were observed, and samples taken for 

 examination showed the usual symptoms in the intestine in this 

 disease. No traces of Nosema were found in either the dead bees 

 examined in pulp or in fresh bees taken individually. 



Early in September the strength was reduced to five frames and 

 the stores were very low. The lesser wax moth was present in fair 

 numbers. The queen continued to lay, and eggs and brood in all 

 stages were present upon three frames. The hive floor was cleared of 

 debris and dead bees, Betanaphthol candy was supplied, and the 

 frames with bees were sprayed with Bacterol. During the next 

 week the bees diminished in numbers, and latterly there were few 

 crawling symptoms. Two frames of stores from a healthy stock 

 were supplied. With reference to the dead bees cleared from the 

 floor, it may be stated that these were pulped and tested for Nosema. 

 Only a very few spores were observed, and indications were that it 

 could not have been present in a widespread form in this stock 

 during these latter weeks. 



The stock dwindled during the next six weeks, although the 

 bees were not showing any signs of disease and the queen laid to 

 the last. The bees were feeding well, being supplied with Bacterol 

 treated candy. Towards the end of October the stock became 

 extinct. One hundred bees were pulped and yielded a negative 

 result for Nosema. The queen also was examined for Nosema and 

 no trace of this parasite was found. 



Notes upon the foregoing history. — Although the Nosema in- 

 fection was accompanied by sac brood disease, it seems clear that 

 this parasite was an essential cause of the failure of the stock to 

 build up in a normal manner. 



The disappearance of Nosema from a stock, such as occurred 

 here, we have noted on other occasions. F"rom a consideration of 

 all the circumstances the re-appearance of Isle-of-Wight disease 

 must be regarded as an entirely new outbreak. Factors of sig- 

 nificance are the weakened condition of the stock from the recent 

 presence of Nosema and of sac brood diseases, and also the 

 situation in which the stock was placed. It stood in an apiary set 

 apart for the experimental study of Isle-of-Wight disease in 

 immediate proximity to other stocks suffering from this disease. 



Altogether the facts indicate that Nosema infection may be quite 

 definitely established in the absence of all symptoms we are 

 familiar with in Isle-of-Wight disease. The fact that when such 

 symptoms eventually appeared in the stock Nosema was either in a 

 latent condition or absent suggests that these two conditions are 

 not causally related. 



No. 9. Failure of Nosema Infection with subsequent develop- 

 ment of Isle-of-Wight Disease.— On the loth, and again upon the 

 15th May 1918, candy infected with Nosema apis spores was fed to 

 a healthy stock of Punic bees (No. 1 2), previously tested for Nosema, 

 with negative results. Examinations of bees for Nosema infection 

 were made upon various dates with the results recorded below. 

 Upon the i8th May ingested spores were found in one bee out 

 of five examined. Again, upon the 24th May, spores were found 



