EXPERIMENT STATION BULDETINS. 297 



by which most American foul-brood is spread. The feeding of honey from 

 diseased colonies which are thought to be healthy, the practice known as 

 "Equalization of Brood," the dividing of brood among weak colonies after 

 shook swarming and other such practices, are often the means of scattering 

 disease throughout the apiary. Frequently in such cases the disease has only 

 begun to appear in one or two cells in the brood nest or else is present in 

 the shape of diseased honey previously robbed from some other diseased 

 colony and not yet actually fed to larvae to produce disease. In many of 

 these cases the beekeeper is not aware that he has spread disease through 

 his colonies until a few weeks later when he discovers the symptoms in the 

 various colonies manipulated. The use of secondhand cans is another 

 questionable practice. Frequently the honey which was shipped in the can 

 contained disease, and the rinsing of the cans previous to use usually exposes 

 a dilution of honey and spores to the bees. Disease is also transmitted from 

 one colony to another by the beekeepers' hands and hive tool. However, 

 this means of spread is not so much to be feared as the others mentioned. 

 Bee-trees in the woods should be promptly attended to by the owner as the 

 occupants of the tree frequently become infected with foul-brood, are killed 

 out during the winter and then remain a source of infection for all bees 

 within flying distance. No doubt this source of infection explains many of 

 the non-traceable causes of infection which beekeepers meet with. The 

 interchanging of supers, combs and other apparatus frequently practiced 

 in extracted honey production is a prolific method of spreading foul-brood 

 and should be carefully guarded against. Each hive, together with all 

 combs, supers and super-covers, should be numbered, thus insuring the use 

 of the same apparatus on the same hive every time. Leaky shipments of 

 honey passing through the country are another means of spreading disease. 

 Frequently apiaries are located within flying distance of railroad switches 

 and leak}^ shipments of honej^ are robbed. The indiscriminate shipping of 

 bees from one state to another or from one section of the state to another 

 without the consent and inspection of a bee inspector is to be guarded 

 against. It is probable that in this way the disease has spread so rapidly 

 over practically the entire United States. 



TREATMENT. 



Bacillus larvae is very resistant to heat, drying, smilight, chemicals and 

 disinfectants. It has been known to live in the scales of a diseased comb 

 for 9 years. It is this resistance to the ordinary means of control of bacterial 

 diseases that makes the treatment of American foul-brood difficult. The 

 treatment for American foul-brood known as the McEvoy or Shaking treat- 

 ment consists of the replacing of the diseased hive, combs and honey with a 

 clean hive and full sheets of foundation, thus forcing the bees to build new 

 clean combs. This treatment should be given during the honey flow to pre- 

 vent robbing or else performed under a tent of wire cloth or mosquito net- 

 ting. When a number of colonies are to be treated, beekeepers prefer to 

 perform the operation during the middle of the day when the majority of 

 the bees are in the field. When only a few colonies have to be treated, the 

 treatment should be given in the evening. If a large number of colonies 

 are to be treated all should be shaken at the same time. Otherwise the 

 danger of robbing is increased. Before treating the colony all equipment 

 needed for the operation should be in readiness. A queen guard, Hghted 

 smoker, hive tool, complete clean hive with full sheets of foundation, a 



