2 CIKCULAE 3 9 2, U. S. DEPARTMENT OF AGRICULTURE 



production. Unless bee diseases are recognized and controlled, indi 

 vidual colonies or even those of entire apiaries may be seriously 

 weakened or destroyed. 



It is important that beekeepers recognize bee diseases in their 

 early stages so that they can apply proper methods of treatment, 

 since practically all the diseases are more or less contagious and can 

 spread from diseased to healthy colonies. Some of the diseases cause 

 cnly slight losses, and can, to a certain extent, be disregarded. Oth- 

 ers, however, are serious, and prompt treatment is required to pre- 

 vent their spread. Consequently it is necessary that the beekeeper 

 be able to recognize even the less serious diseases so as not to con- 

 fuse them with the serious ones. The symptoms of sacbrood and 

 European foulbrood, for instance, are often confused with those of 

 American foulbrood. Furthermore, American foulbrood may be 

 mistaken for European foulbrood, and if the usual treatment for 

 the latter is applied, the disease not only will not be arrested but is 

 likely to spread to healthy colonies. 



In recent years new bee diseases have been discovered. One of 

 these, parafoulbrood, a serious brood disease, at present appears to 

 exist only in limited sections of the South. It is highly desirable 

 to prevent the further spread of these newly discovered diseases and, 

 consequently, beekeepers should learn to differentiate them from the 

 other more widely distributed diseases. 



There are also a number of abnormal conditions of bees that at 

 times cause heavy losses and can easily be confused with some of 

 the diseases. It has recently been found that nectar or pollen, or 

 both, from certain plants may cause the poisoning of brood and adult 

 bees. Then, too, the symptoms of poisoning or other abnormal con- 

 ditions of bees such as chilling, starvation, or the presence of brood 

 of infertile queens or laying workers, can easily be confused with 

 the symptoms of some of the diseases. 



No attempt has been made in this circular to describe methods of 

 treatment, since these are available in other publications of the 

 Department of Agriculture and in State bulletins and other bee- 

 keeping literature. Abnormal conditions of bees that are often 

 difficult to distinguish from diseases are not discussed in detail, 

 since it is planned to describe them in another publication. 



BROOD DISEASES 



WHAT TO OBSERVE WHEN LOOKING FOR BROOD DISEASES 



To identify the brood diseases, any dead brood found in the cells 

 should be examined carefully. The appearance of the combs may 

 indicate which brood disease is present, but final diagnosis should 

 always depend upon the symptoms shown by the dead brood. Dead 

 brood in open cells can be seen clearly if a comb is held so inclined 

 that the direct light of the sun falls on the lower side and bottom 

 of the cells (fig. 1). If there is no dead brood in the open cells, 

 any sunken, discolored, or punctured cappings should be removed 

 and these cells examined for dead brood. 



When dead brood is found, the following important points should 

 be determined; (1) Age of the brood when death occurred, (2) po- 



