liee-keepiiiti in Victoria. 79 



•other hives, attracted by the commotion, join in and share in the phmder. 

 As colonies affected with foul brood are poor defenders of their home, 

 such a colony, if on© is in the apiary, usually falls a victim to the robbers 

 and the robbers in turn develop disease in their hives. Combs, removed 

 from the hives should be at once secured from access by bee moths, by 

 tiering the cases and securely covering the top and bottom of each stack. 

 It is during the autumn that tli© wax or bee moth deposits its. eggs on 

 the combs, although the grubs do not appear till spring. Often the bee- 

 keeper is unaware that the eggs were present when he carefully packed 

 away his combs, after leaving them exposed to the motlis for a little 

 time. 



XIX. — Diseases of Bees. 



The diseases affecting bees may be grouped under two headings, 

 viz., diseases of the adult bee and diseases of the larva;, or brood. The 

 latter diseases are the more generally distributed and serious, and the 

 principal ones are known under the general term of foul-brood of bees. 



Foul-brood. 



This is a contagious disease which kills the young larval bee in the 

 ■cell. By contact with the remains of the dead grub the disease is 

 transmitted by the adult bees to other cells, thus causing the death of 

 the larvcC from eggs deposited in such cells or the contamination of 

 any honey stored in them. 



As the average life of the worker bee during summer is only six 

 weeks, it follows that the number of young bees hatching decreases as 

 the disease advances, the colony soon dwindles in numbers until it 

 finally dies right out or becomes so weakened as to be unable to defend 

 itself against robber bees from other hives. The honey is carried 

 away by bees from other colonies, which in turn become infected, thus 

 ■propagating the disease indefinitely. 



The methods of box-hive bee-keepers, however, have done more to 

 rspread disease than anything else. The usual way is to drum the bees 

 -out of the upturned hive into an empty box, to cut out the combs, and, 

 after crushing- them and straining the honey off. to throw out the resi- 

 •due, and any combs too black for straining, for the bees to clean up. If 

 any of the hives were diseased, the germs are at once re-introduced 

 into the newly-built combs of the robbed hives, while the contaminated 

 honey, when marketed, carries infection to distant localities by means 

 ■of bees getting access to retail packages after they have been emptied 

 •and thrown away. 



The cause of foul-brood is a micro-organism growing in the tissue 

 •of the larvffi of the bee and sometimes also in the adult insect. It was 

 named Bacillus alvei by Cheshire and W. Cheyne in 1885. Since 1912 

 American investigators have discovered that there are three types of 

 foul-brood, European Foul-brood caused by Bacillus pluton, American 

 Foul-brood caused by a micro-organism differing from the former and 

 named Bacillus larvce by Dr. G. F. White, of United States Depart- 

 ment of Agriculture, and Sac-brood caused by a filterable virus. The 

 general appearance of the diseased brood is, however, the same m all. 



