44 



BULLETIlSr 780, V. S. DEPARTMENT OF AGRICULTURE. 



As will be observed from Table XXVI, infection did not occur in 

 any of the experiments in which brood-combs from Nosema-infected 

 colonies were given to healthy ones. The practical import of the 

 results is that brood-combs from Nosema-infected colonies need not be 

 destroyed, but may be inserted without treatment into hives contain- 

 ing healthy bees with practically no fear that losses will result from 

 such manipulation. (See also experiment No. 2, p. 25.) 



RESISTANCE OF NOSEMA APIS TO CARBOLIC ACED. 



Stomachs taken from Nosema-infected bees were crushed and 

 suspended in aqueous solutions of carbolic acid (commercial). One, 2, 

 and 4 per cent solutions were used. These suspensions, respectively, 

 were distributed in test tubes and were allowed to stand at room 

 temperature. After different intervals healthy colonies were inocu- 

 lated, the suspension from a single tube being used for each. 



A summary of experiments performed with the results obtained is 

 given in Table XXVII. 



Table XXVII. — Effect of carbolic add on Nosema apis. 



Date of inoculation. 



Per cent 

 of car- 

 bolic- 

 acid 



solution. 



Period in carbolic 

 acid. 



Results of inoculation. 



Aug. 18, 1915 

 July 16, 1915. 

 July 2, 1915.. 

 June 9, 1915., 

 Aug. 18, 1915 

 July 16, 1915. 

 July 2, 1915.. 

 Junes, 1915. 

 July 16, 1915. 

 July 2, 1915.. 

 Junes, 1915., 



Hours. 

 

 1 

 6 



51 

 

 1 

 6 



27 

 1 

 5 



27 



Minutes. 



10 

 

 

 



10 

 

 

 

 

 

 



No infection produced. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



From the preliminary results given in Table XXVII it will be noted 

 that Nosema apis is rapidly destroyed in 1, 2, and 4 per cent aqueous 

 solutions, respectively, of carbolic acid, showing that the parasite 

 possesses very slight resistance to the disinfectant. 



EFFECT OF DRUGS ON NOSEMA-DISEASE. 



It is natural that beekeepers should have thought of drugs and 

 employ them in the treatment of Nosema infection. Preliminary 

 experiments have been made to obtain data relative to the effect of 

 betanaphthol, salol (phenyl salicylate), carbolic acid (phenol), salicylic 

 acid, formic acid, oil of eucalyptus, and quinin (bisulphate of 

 quinin) on this infection. It will be recalled that most of these 

 drugs have been given a trial from time to time by beekeepers in the 

 treatment of one or more of the bee diseases. 



