UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 431 



OMribntlon bom the Bnraau of Entomoloir 

 L.O. HOWABD, Chief 



^Bshlngton, D. C. 



PROFESSIONAL PAPER 



February 9, 1917 



SACBROOD 



By 



G. F.^^TTE 

 Expert, Engaged in the Investigation of Bee IMseases 



CONTENTS 



Page 



, 1 



Btatoctnl Account ......... 2 



NmmeoftheDInase 4 



Appearance of Healthy Brood at the Ate 



atWhtehttDicBofSacbraod .... 6 



SymptoiiMof Sacbrood 10 



Cause of Sacbtood 24 



WeakenlnK Effect of Sacbrood Upon a 



Colony 30 



Amonnt of Tims Beqnired to Produce 



Hut Dlaease. and the Bapldtty of ita 



. bwreaae . . .' 31 



Methods Oaed in Makint Experimental 



InaenlatlanB . 32 



Means for the DeatmcUoit of the Vlnu of 



Sacbrood 



BcatlncBeviited to Destroy Sacbrood 



Vbua when Suspended In Water ' . . 

 Beatlns BeqnlreC to Destroy Sacbrood 



Tims Vhen Suspended In Glycerine . 

 Beating Required to Destroy Sacbrood 



Tints When Suspended in Honey . . 

 Bealatanee of Sacbrood Tbua to Dtyins 



at Boon TMnpetattura 



87 



Page 

 BiBstotsBet of Saebmod Tlras to Direct 



Sunlight When Dry 38 



Besistance of Sacbrood Tiros to Direct 



Sunllcht When Suspended In Water . 39 

 Besistance of Sacbrood Tims to Direct 



SunllEht When Suspended In Honey . 40 

 I.enith of Time that Sacbrood Tims Be> 



- mains Timlent In Honey 40 



Besistance ofSacbroodTlrastothe Pres. 



once of FermentatlTe Processes ... 41 

 Besistance of Sacbrood Tims to Fer. 



mentation in Diluted Honey at Out> 



door Temperature 42 



Besistance of Sacbrood Tims to the Pres< 



enee of Putrefocllve Processes ... 43 

 Besistance of Sacbrood Tims to Carbolic 



Acid 44 



Modes of Transmission of Sacbrood . . 46 



Diagnosis of Sacbrood 48 



ProKnoBla ............. 49 



Belatlon of These Studies to the Treat* 



ment of Sacbrood . 50 



Summary and Conclmdons ...... S2 



Literature Cited. fiS 



WASBINOTON 



GOTEBNMENT PBINTIKO OlflCB 



1917 



