EXPERIMENT STATION BULLETINS 307 



Foul brood is a disease of bees common in all parts of the State of Michigan and one 

 which is fast mining a most pleasant and profitable industry. It spreads through 

 an apiary, affecting the strongest as well as the weakest colonies, because it is one of 

 those malignant and contagious diseases due to the presence of a germ called by the 

 scientists bacillus alvei. Adult bees are supposed to be beyond the reach of this germ, 

 and the disease is therefore confined to larva between the ages of one and ten days. 

 Just how this young larva becomes affected is not definitely known. It may be through 

 contagion from the diseased comb or brood which contagion is brought to the young 

 larvip by the nurse bees, but in all probability the germ is introduced with the food. 

 It has been said that foul bood develops from chilled or starved brood. This has 

 been proven beyond a doubt not to be true. Since it is a germ disease it cannot 

 develop when the germ which causes it is not present. On the other hand, the disease 

 is so highly iHleetk)us that one drop of infected honey may ruin a whole apiary. 



SYMrTOMS. 



The first apparent evidence of the presence of the disease manifests itself in the 

 behavior of the bees wliicli do not seem to possess their usual activity but have a 

 lazj^ indolent manner. There is apt to be some litter in the entrance of the hive as 

 though the bees were loatli to ''clean house." A few bees may fan at the entrance. 

 After the disease is mcU advanced a foul smell resembling melting glue may be 

 detected without removing the cover even, and at some little distance from the hive. 



On removing the cover an examination of an infected colony reveals the following 

 peculiarities: The brood is not compact, but scattered. The empty cells, those not 

 containing brood, may contain a dr\' scale in the bottom. The cappings over the 

 dead larvae are depressed slightly and darker than the healthy ones. There is often a 

 hole in the center of the cap. Many lai'va^. however, die before the cell is sealed. 



If the examination is made when the disease is just beginning, the aflt'ected larvae 

 are no longer curled tip, but either lie extended in the cell or are moving about un- 

 naturally. As the disease progresses they lose their plump appearance, become 

 flabby and finally die. 



As' decomposition begins the larvae at first take on a yellowish appearance, and 

 later turn brown. If a toothpick is inserted into the dead larvne at this time and 

 later and is slowly dra^^•n out it will show a long, ropy tenacious string, which upon 

 breaking, when drawn out to its fullest extent, flies back into the cell. This ropy, 

 putrid mass slowly dries down and adheres to the bottom of the cell, forming a small 

 scale. The bees seem reluctant to remove these dead larvae, instead of hastening their 

 removal as they do in other instances when larva? die. Or it may be that the dead 

 larva- adhere so firmly to the cell that it is impossible for the bees to remove them. 

 \\ hatever the cause may be, when the larvaj are killed by this disease they are 

 not removed. 



As a result of the disease the colony becomes weakened since the brood fails to 

 hatch, and soon dwindles down to such an extent that it is utterly defenseless and 

 is then liable to be robbed. As soon as the robbing begins the disease is transferred 

 to other colonies, and unless the bee-keeper is watchful the whole apiary becomes 

 infected. 



It has been said '"a bee-keeper who does not discover foul brood before his nostrils 

 remind him that something is wrong is no man to treat the disease."' It would be 

 more proper to say that a bee-keeper who does not discover that something is wrong 

 before his nostrils tell him of the presence of foul brood is no man to treat the dis- 

 ease, for foul brood is often foimd in the apairy of an owner who was not acquainted 

 with it, but who after having been instructed as to its nature and treatment has 

 efTecied a complete cure. Dr. Howard saj-s, "I regard the use of any and all drugs 

 in the treatment of foul brood as a useless Avasto of time and material, wholly 

 ineflcctual, inviting ruin and total loss of bees. Any metliod which has not for its 

 object the entire removal of all infectious material beyond the reach of bees and 

 brood will prove detrimental and destructive and surely encourages the recurrence 

 of the disease." 



The one method that has given the most universal satisfaction is recommended 

 by Canada's inspector of apiaries, William McEvoy. His method is given below 

 in his own words: 



