ing larvae dead of American Foulbrood are first a li&ht yellow brown As 

 they settle down in the cell the colour changes gradually to a dark, coffee 

 brown, which is of uniform shade over the entire body surtace. 



Avvearance of affected pupae. Pupae dead of the disease go through 

 the same process of decay and settling and similar colour changes as the 

 larvae. The tongue of the pupa is nearly always extended towards the 

 top wall of the cell. This is a definite sign of American Foulbrood. 



Ropiness of American Foulbrood. American Foulbrood destroys the 

 larval or pupal tissue. The body wall soon becomes soft and easily rup- 

 tured. Dead brood passes through several stages of decay, each stage 

 varying in colour, shape and consistency. After about three weeks of 

 decay, until the scale is formed, a characteristic ropiness is exhibited. 

 During this period a toothpick inserted into the mass will draw out a fine 

 gluey thread of decaying matter. (Fig. 2.) 



The ropiness of American Foulbrood 

 (U.S. Dept. Ag., Far. Bui. 442) 



Although this ropiness is a definite characteristic of American Foul- 

 brood, it should be remembered that it only occurs at a certain stage of 

 putrefaction. When a suspicious cell is found during inspection, all 

 other symptoms should be carefully observed before inserting a toothpick 

 and destroying the larva or pupa for further inspection. Too many 

 beekeepers have the habit of inserting a toothpick immediately they see a 

 suspicious cell. 



This destroys other important symptoms. 



American Foulbrood odour. In the early stages of American Foul- 

 brood no odour is evident. In advanced stages, however, where much 

 brood is dying and the disease has been present for weeks, the odour is 

 quite distinct. The smell is characteristic, but is probably best described 

 as resembling that of heated glue. 



The value of odour is overlooked by many experienced beekeepers. 

 Even when a small amount of infection is observed a diseased larva may 

 be removed on a match or toothpick and an effort made to detect the 

 characteristic odour. Some people have a very highly developed sense of 

 smell and with such this point is a great help in diagnosis. 



Formation of a Scale. After four to five weeks the decaying brood 

 dries down to a hard dark scale. American Foulbrood scales are char- 

 acteristically uniform in shape, covering the greater portion of the lower 

 cell wall and extending part way up the back wall. The scale adheres 

 tightly to the cell and cannot usually be removed without tearing the cell 

 wall. 



