11 



Distribution: Sacbrood has occurred quite generally in all localities 

 of the United States and Canada. Its effects have never been serious 

 and consequently it has not received the attention that it really de- 

 serves. It occurs frequently in Iowa, with no partciular regard to lo- 

 cality. It is more commonly associated with European foulbrood than 

 ■with American, but is not so restricted to black bees. 



Common Name: The name is quite distinctive of the condition In 

 ■which the larvae are found after death. The appearance of the dead 

 larvae has been likened to a sack of wheat tightly tied at the top end. 



Diagnosis: Sacbrood is infectious, altho the specific organism has 

 not been isolated. It is transmitted by the nurse bees in feeding the 

 young larvae. Sick larvae when used experimentally will produce 

 the disease again in healthy larvae. The larvae die usually after 

 the cell is sealed, but very often the bees have entirely taken away the 

 capping, so it appears that the larvae die before they are capped. The 

 larvae swell until there is no trace of the segments or divisions of the 

 hody. Their color might be termed gray, altho in some instances there 

 is a tendency to a yellowish tint, but hardly enough to be called brown. 

 The tightly tied sack appearance is very characteristic. Another 

 characteristic of this disease is that the skin of the larva becomes al- 

 most parchment like in texture. Therefore, it is very easy to remove 

 the larva from its cell without puncturing the body wall; in fact, if 

 the comb is tipped up and shaken, the larva will drop out. The con- 

 tents of the larva are very watery in consistency. These symptoms 

 are very characteristic and are sufficiently different from either Amer- 

 ican or European foulbrood so that it should be possible to make a 

 diagnosis. 



Seasonal History: Sacbrood seems to be more common during the 

 spring and especially when unfavorable weather conditions prevail, 

 as is the case with European foulbrood. It is more common with the 

 black and hybrid bees than with the Italian bees, altho the correlation 

 is not as positive as is the case with European foulbrood. It works 

 much more slowly in the colony than European foulbrood and more 

 often a colony will overcome the disease and perhaps regain in strength 

 by the end of the honeyflow. It is seldom found during the summer 

 honeyflow. 



Treatment: Better management seems to lend itself exceedingly 

 well to control of sacbrood. The first considdration is to re-queen the 

 colony which is affected. This can be accompanied with a stimulative 

 feed and it may be advisable to add a frame or two of sealed brood 

 from some strong colony. Under these conditions a colony will re- 

 cover very' rapidly and the disease will probably not appear again in 

 that colony. 



MISCELLANEOUS DISEASES 



Closely associated with American and European fulbrood and Sac- 

 brood are minor disease and physical conditions which may be con- 

 fused in making a diagnosis for a brood disease. Before sacbrood was 

 definitely named, beekeepers frequently referred to a so-called dis- 

 ease, "pickled" brood. With the coming of better methods of beekeep- 

 ing this so-called disease has practically disappeared from the apiary. 

 Occasionally brood will decay in a manner which is not typical of any 

 other brood diseases which have been described. This may be the 

 result of a specific organism, but more often it is a condition rather 

 than a disease. In the majority of cases the term "pickled" brood has 

 been applied to sacbrood and as a specific disease is not of Importance. 



