92 histoeical notes on bee diseases. 



^Iaassen and Nithack, March, 1910 



Simultaneously with the paper just considered there was pub- 

 lished a paper ^ on bee dysentery by Maassen and Nithack. Dead 

 adult bees from entirely isolated localities were received and exam- 

 ined. There was a history of supposed poisoning accompanying the 

 bees. No cause for their death, however, could be found. It is 

 recorded that no Nosema apis was found. 



The first dysentery observed by these men was in two colonies 

 taken from different apiaries. One was a queenless two-frame 

 nucleus and the other a queen-right colony of six frames. These 

 two colonies were transferred to wire cages. After about three 

 weeks symptoms of dysentery were observed. At the beginning of 

 the spotting Nosema apis was not found in the excrement, but could 

 be demonstrated in the mid-gut. Several days later, when the 

 intestine showed the appearance described by Zander, the parasite 

 was found in the intestine. 



These findings caused Maassen and Nithack to confine in wire 

 cages a series of small queenless colonies. These cages were kept in 

 a room whose temperature ranged from 14° to 16° C. The bees were 

 obtained from different sources, and all chances of becoming infected 

 from food, hives, or combs subsequent to being taken into the room 

 were excluded. The results obtained from this experiment were 

 similar to those of the preceding one. Other experiments somewhat 

 similar were performed. 



These men report that in many colonies in which no visible signs 

 of dysentery were present there were found bees containing Nosema 

 apis. They beheve that among bees this protozoan is wddely dis- 

 tributed. Up to the time of their writing they had not failed to find 

 it in colonies that were suffering from dysentery. 



Malden, June, 1910. 



In 1910 Maiden in a paper ^ gave a good brief review of the status 

 of the present knowledge of bee diseases. He gives some further 

 observations concerning the Isle of Wight disease. Referring to 

 Bacillus pestiformis apis (p. 87) he writes in part as follows: 



This organism may frequently be found to have penetrated between the cells of 

 the lining membrane of the chyle stomach and to be present in large numbers in the 

 loosened tissue behind the secreting cells. It has been found present in about 60 

 per cent, of all the bees affected with this disease which have been examined . * * * 

 It appears highly probable that this organism is the cause of the disease, but up to the 

 present time no infection experiments have been successful in XJroducing the com- 

 plaint in healthy stocks, so that its relation to the disease cannot be said to be proved. 



1 Maassen und Nithack, March, 1910. Uber die Ruhr der Bienen. Mitteilungen aus der kaiserlichen 

 biologlschen Anstalt fiir Land- und Forstwirtschaft, Heft 10, pp. 3&-42. 



« Maiden, Walter, M. A., M. D., June, 1910. Diseases of bees. Reprinted from The Journal of Economic 

 Biology, Vol. V, Pt. 2. Pp. 41-48. 



