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greyish white in colour. This greyish colour turns to a greyish brown 

 tint which deepens as the process of decay continues. Throughout this 

 period of decay the head end appears somewhat shrunken and much 

 darker than the more posterior, or hind, portion of the body. 



Consistency of dead larva. The body wall of a larva dead of 

 Sacbrood becomes toughened and may be easily removed mtact from the 

 cell. When removed from the cell the larva is sac-like in appearance. 

 The contents of the sac are watery, containing many fine brown granules. 



Odour. Sacbrood has no distinctive odour. 



Scale formation. Scales formed from sacbrood are greyish black, 

 roughened and generally curl up at the anterior or head ends. Scales are 

 not common as the bees generally remove the dead larvae before the scale 

 is formed. When present they are loose in the cell. 



(b) Cause op Sacbrood 



No organism has been found present in dead larvae which can be 

 demonstrated to cause the disease. It has therefore been concluded that 

 the disease is caused by a virus which will pass through the finest of 

 filters. A colony may be inoculated with the disease by feeding syrup or 

 honey containing the virus from dead larvae. 



(c) Spread of Sacbrood 



Sacbrood virus is readily destroyed. Larvae dead of Sacbrood cease 

 to be infectious after one month. How the disease winters over is not 

 known. Colonies infected in the spring generally recover during the 

 honey flow. The weakening effect of the disease during the spring stays 

 with the colony throughout the honey flow. 



(d) Control Measures 



Vigorous colonies rarely suffer to any extent from Sacbrood. Re- 

 queening and strengthening will generally clean up any infection that 

 may occur. It is never necessary to destroy any part of a hive infected 

 with Sacbrood. 



FUNGOUS DISEASES 



Fungous diseases, although never particularly serious, cause consid- 

 erable damage in the aggregate loss of bees. There are many types of 

 fungi affecting bees both as brood and adults. Conditions such as the 

 so-called stone brood and chalk brood are typical of the work of fungi. 

 The dead remains become dry and mummified. Molded combs and equip- 

 ment and mouldy fruits, etc., are believed to cause the infection. 



DISEASES OF ADULT BEES 



To date there has been no serious trouble from adult bee diseases in 

 any part of Canada or the United States. In England and other parts of 

 Europe they have caused great loss. It is necessary that we know some- 

 thing of the symptoms of these diseases and be ready to stamp out any 

 infestation that might occur. 



