606 IOWA DEPARTMENT OF AGRICULTURE 



Symptoms of Sacbrood. 



"The strength of a colony in which sacbrood is present is fre- 

 quently not noticeably diminished. When the brood is badly in- 

 fected, however, the colony naturally becomes appreciably weak- 

 ened thereby. The brood dies after the time of capping. The 

 dead larvae are therefore always found extended lengthwise in 

 the cell and lying with the dorsal side against the lower wall. 

 It is not unusual to find many larvae dead of this disease in un- 

 capped cells. Such brood, however, had been uncapped by the 

 bees after it died. In this disease the cappings are frequently 

 punctured by the bees. Occasionally a capping has a hole through 

 it, indicating that the capping had never been completed. A 

 larva dead of this disease loses its normal color and assumes at 

 first a slightly yellowish tint. 'Brown' is the most characteristic 

 appearance assumed by the larvae during its decay. Various 

 shades are observed. The term 'gray' might sometimes appro- 

 priately be used to designate it. The form of the larva dead of 

 this disease changes much less than it does in foul brood. The 

 body wall is not easily broken as a rule. On this account often 

 the entire larva can be removed from the cell intact. The content 

 of this sac-like larva is more or less watery. The head end is 

 usually turned markedly upward. The dried larva or scale is 

 easily removed from the lower side wall. There is practically no 

 odor to the brood combs." 



SOURCES OF CONTAGION. 



The spread of foul brood in the immediate neighborhood of the 

 diseased colonies is usually by means of robber bees which visit 

 those which because of their weakened condition are no longer 

 able to defend their stores, and the disease is thus rapidly spread. 

 Every bee keeper should be very careful to guard against the 

 robbing of weak colonies. In case a colony dies from disease the 

 hive should be at once removed, the contents destroyed, and the 

 hive and fixtures thoroughly disinfected. 



The past season I had occasion to visit an apiary where disease 

 was suspected and found that when a colony had died the owner 

 had opened it up and exposed the contents to the bees. As a re- 

 sult foul brood had been spread throughout his entire apiary and 

 others of the surrounding neighborhood. In this case the owner 

 was unaware that his bees were diseased and as a result his loss 

 will be heavy. 



