BEES IN COLONIES AFFECTED BY EUROPEAN FOULBROOD 



15 



a hybrid queen in a diseased Italian colony, but the presence of the 

 heavy honey flow made it impracticable to carry the matter further. 

 This colony A cleaned up readily after removal of the queen and 

 was reported all healthy in August. Although a new queen was 

 given to them it is probable that a period of queenlessness and the re- 

 turning of the same queen would have answered just as well. 



Race. — Italian. 



Queen. — 1917, fairly good condition. 



Condition of colony at time of infection. — Seven frames of emerging 



brood well covered witli young bees. A strong 8-frame colony. 

 Date of first infection.— 3n\y 10, 1918. 

 Material used. — Thirty diseased larvse from sample No. 5959, macerated 



in 250 c. c. of a 50 per cent sugar sirup. This was abnormally heavy 



infection of diseased material. 

 First appearance of disease noted. — July 15, 1918, five days after infection. 

 Age of larvce first attacked. — Four days after hatching from the egg. 



This colony was infected during the heavy honey flow, but 

 although given a heavy infection it had sufficient strength, aided by 

 the heavy honey flow, to prevent the disease from spreading. On 

 July 15 there were a few diseased larvse in two combs. On July 24, 

 14 days after inoculation, there were only a few diseased larvse in 

 three combs. This was after the queen had been removed on July 

 18 and the colony had been united with colony H on the 20th. 



An interesting observation was that under the magnifying glass 

 the methods of the nurse bees in sucking the juices from dead dis- 

 eased larvse and the pulling of the skins out to carry them away could 

 be noted. No bee worked very long at a time on one larva. One 

 after another worked until all was completed. 



SUMMARY OF PREVIOUS EXPERIMENTS 



Table I gives a partial summary of the data thus far described. 



Table I. — Showing the first appearance of disease noted after infection. Also 

 the number of cotnhs shoxving infection and the spread of the infection from 

 comb to comb in the various colonies under observation 



Col- 



Date 

 infected. 



Days after infection. 



ony. 



1 



2 



3 



4 



5 



6 7 



8 



9 



10 



11 



12 



13 



14 



15 



i.6 



17 



18 



19 



20 



21 



22 



23 



24 



25 



26 



27 



28 





1918 

 May 28 

 May 31 

 /July 1 

 IJuly 8 

 /July 2 

 IJuly 6 

 July 10 



Number of combs. 



Gi... 



i 



-• 



1 



3 

 2 



"z 



2 



4 

 3 



5 

 2 



4 



'4 

 1 



7 





































8 



Fi.... 







5 















6 









7 



... 









H«.... 





2 







4 

 < 























A».... 





... 



3 



Dif 



5 

 Terp 













4 













P 



nt 



jon 



1 first t 



wo 



) 







































' Experiments started before the beginning of the heavy honey flow. 

 « Experiments started after the beginning of the heavy "honey flow. 



