17 



Cappings 



Time of 

 Death 



Position in 

 the Cell 



Colour 

 Changes 



Appearance 

 of Pupa 



Consistency 



Tracheae 

 Odour 



Scale 



COMPARISON OF BROOD DISEASES 



A. F. B. 



Many sunken, dark 

 and perforated. 



During prenupal stage 

 or within two days 

 after transformation 

 to pupa. 



Straightened out, 

 regular and uniform. 

 Occupies most of lower 

 cell wall. Posterior, or 

 hind end, extending up 

 back wall of cell. 



From light yellow- 

 brown to dark coffee- 

 brown. Uniform 

 throughout. 



Same process of decay 

 as larva, tongue 

 extended upwards. 



Soft mass. Exhibits 

 ropiness at certain 

 stage. 



Not visible. 



Odour of heated glue 

 in advanced stages. 



Hard, dark, uniform 

 scale. Adheres tightly 

 to cell. 



E. F. B. 



Usually none. When 

 larvae in advanced 

 stages of development, 

 capping, sunken, 

 perforated and greasy. 



Before change to pupa. 

 Generally quite early 

 and before capping. 

 Advanced larval stages 

 often cauped. 



90% of cases curled in 

 the cell and in unnat- 

 ural positions. 10% 

 in advanced larval 

 stages fairly regular 

 and extended in the 

 cells. 



Prom greyish-yellow 

 to dark greyish brown. 

 Not uniform. 



Sacbrood 



From a light yellowish- 

 grey to dark brown. 

 (Head end darker. 



Nione die. 



Somewhat stioky and 

 granular. 



'Often plainly visible. 



Fishy odour in 

 advanced stages. 



Ruiblber-like, irregular. Black, roughened 

 shrivelled, dark brown curled up at anterior 

 scale. lEasilv removed, or head end. 



Many uncapped; some 

 perforated. 



Before change to pupa. 

 After capping. 



Uniform shape and 

 position in cell with 

 head end curled up. 



None die. 



Bodv wall tough, 

 contents watery. 



Not visible. 

 No odour. 



A considerable proportion of the cappings are uncapped by the bees, 

 a rule the proportion of brood affected is not large. 



As 



Time of death. Affected larvae die after the cells are capped but 

 before the change to the pupal stage is completed. The majority die 

 during the two days prepupal period, i.e. within the two days preceding 

 the transformation. Many uncapped cells are generally observed on 

 diseased combs but they are uncapped by the bees after the death of the 

 larvae. 



Position in the cell. Dead larvae are extended lengthwise along the 

 floor of the cell. The position is similar to that of larvae affected with 

 American Foulbrood. Sacbrood, however, can be determined by the 

 appearance of the head which is dark, somewhat shrivelled and turns up 

 towards the roof of the cell. 



Colour changes. Soon after death the larval remains are slightly 



