Dkckmber, 1922 



a h !•; A N I N r. s in b e k o it l t u r k 



foul brood, I would mark tlie location of 

 this larva and watch that colony until sure 

 whether the disease is present or not. 

 Experiments Began Early in 1921. 



At the end of the season of lOLlO, I liad 

 several colonies showing advanced stages 

 of American foul brood. The combs were 

 as perfect as are to be had, so I hesitated 

 to destroy them in the usual way of getting 

 rid of American foul-brood combs. The de- 

 struction of a nice lot of combs, because 

 they Avere occupied by bees afflicted with 

 foul brood, has always appealed to me as a 

 big loss. These combs w'ere stored away 

 in a place safe from robber bees. During 

 the early spring of 1921, I started experi- 

 menting with a number of disinfectants 

 which were dissolved in water. I came to the 

 conclusion that a disinfectant dissolved in 

 water showed little hopes of success, be- 

 cause the disinfection of a honeycomb con- 

 taining dead larvae due to American foul 

 brood presents a peculiar diiiiculty. 

 Difficulties in Way of Disinfecting Combs. 



In the first place, such a honeycomb as or- 

 dinarily occurs in the brood-nest usually con- 

 tains more or less honey. HoAvever, this 

 honey, by extracting, is easily disposed of. 

 After removing the honey, the brood-comb 

 consists of beeswax, w^liich, together with 

 the wood surrounding the comb, may be 

 more or less covered with propolis. This 

 resinous substance may be present in quan- 

 tities ranging from lumps, half the size of 

 a hen's egg, to mere thin stains. Numerous 

 cells of the comb may be filled with pollen, 

 which is mostly a protein substance. Most 

 important of all are the cells containing 

 dead larvae in all the different stages char- 

 acteristic of American foul brood. These 

 cells may be sealed or unsealed. The larvae 

 may be hard dried-down scales adhering 

 firmly to the cell walls, or they may be the 

 soft gluelike ropy masses usually described. 



To sum up, after removing the honey 

 from a diseased brood- comb, the comb con- 

 sists of beeswax, propolis, cells filled with 

 pollen and cells containing dead larvae. 



Success in sterilizing a honeycomb made 

 up of the above constituents will only be 

 attained with a substance that has the 

 Droperty of penetrating these substances. 

 The fact is established that anv part of the 

 interior of a beehive infected with American 

 foul brood is liable to be covered by dis- 

 ease germs. Bees are continuouslv carrying 

 bits of propolis and other matter, as is 

 shown by the travel-stains on new comb. As 

 a result, there may be countless numbers 

 of germs buried in masses of propolis, or 

 worked into the wax that goes to form a 

 comb. Hence come the failures that are due 

 to disinfecting with gases, as formaldehyde 

 gas: likewise, watery disinfectants, because 

 neither beeswax nor propolis are penetrated 

 by water in a reasonable length of time. 

 Substance Must Penetrate Beeswax, Propo- 

 Us. Pollen and Dead Larvae. 



Thus, the problem of disinfecting a comb 



containing American foul brood resolves it 

 self into finding a substance that will pene- 

 trate beeswax, propolis, pollen and the dead 

 larv.ne, in sealed or unsealed cells either in 

 the form of dried scales or the ropy gluelike 

 state. Also, this substance must not destroy 

 the wood of the frame, the Avires supporting 

 tlie cnnib, or the comb itself. None of the 

 disinfectant must remain as a residue to 

 endanger the bees Avhich are to occupy it. 

 The substance must be cheap enough to 

 make it practical for commercial use. 



There are many substances Avhich Avill 

 nenetrate beeswax and propolis, as gasoline, 

 benzol, carbon bisulphide, carbon tetrachlo- 

 ride, alcohol, etc. But none of these alone 

 has any A'alue as a disinfectant for Ameri- 

 can foul brood. 



One of the best substances for destroy- 

 ing the germs of American foul brood has 

 been found by the Bureau of EntomologA-, 

 Washington, D. C, to be formaldehyde. 

 ^Bulletin No. 809, American Foul Brood, 

 by G. F. White.) The germs when placed 

 in a strong solution of formaldehyde, are 

 dead after a feAv hours. Fortunately, it has 

 no damaging effect on honeycomb, AA'ire or 

 wood; nor does it leave a residue on the 

 combs after drving. Now, if this be mixed 

 Avith some substance that Avill penetrate 

 beeswax and propolis, an ideal disinfectant 

 AA'ill be obtained. 



The number of substances with Avhich for- 

 malin AAdll mix that are capable of pene- 

 trating beeswax and propolis are \'ery few, 

 oTilv one being worthy of consideration. 

 This one substance is alcohol. 



Alcohol containing 20 T>er cent of forma- 

 lin is a liauid of Ioaa'- sm-^nce tension. This 

 property makes it capable of promptly fill- 

 ing all emptA^ space in the honeycomb. 



In treating a comb containinsr diseased 

 cells of American foul brood, with alcohol 

 containing 20 per cent of formalin, one 

 maA^ obserA'e the folloAving points: 



1. BeesAvax .absorbs the solution: conse- 

 quently, it swells up, as is shown by the dis- 

 tortion of the cell Avails of a comb that has 

 been soaked at least 24 hours. 



2. Propolis is completely penetrated, as it 

 is made semi-liquid by the solution, because 

 propolis is a resinous substance. 



8. Cells filled with pollen are penetrated, 

 because after drA'ing, these masses of pol- 

 len, due to shrinkage, may be shaken, occa- 

 sionalh'-, out of the cells. 



4. Diseased larvae are completely disin- 

 fected, because after dryine:, they, in a 

 hardened condition, can readily be removed 

 from the cell wall. Before dryiup-, the 

 characteristic ropiness is absent. Sealed 

 cells containing diseased larvae are found 

 to be in the same condition. The larvae 

 are no longer repulsiA^e to bees, as the ropy 

 cluelike remains are hardened, and can eas- 

 ily be remoA-ed hv the bees, as so much in- 

 ert matter. 



5. A surface Avct Avith honey is disinfected. 



