Visual symptoms of American foulbrood

Overview of AFB symptoms

Symptoms of AFB are normally only found in worker larvae and pupae. (On rare occasions, symptoms will be found on drone brood (generally only in heavy infections). Symptoms of the disease are also ocassionally found in queen cells.)

What follows is a brief visual snapshot of each of the main symptoms of AFB. For more on each symptom, click on each heading below.

Cell capping colour

 
 
Figure 8: Healthy cell capping Figure 9: Dark sunken cell capping

Holes in cell cappings

Figure 10: A cell capping with a hole
chewed in it

Spotty brood pattern

 
Figure 13: Spotty brood pattern

Colour of brood

 

Figure 15: Healthy prepupa

Figure 16: Coffee coloured AFB


Shape of brood

 

Figure 19: Early stage AFB
infected pupa
 
Figure 20: A very early stage
AFB infected prepupa slumped
on the lower cell wall 
Figure 21: An early stage
AFB infected prepupa
slumped on the lower cell wall


Position in cell

Pupal Tongue

 

 

Figure 17: Pupal scale with tongue
Figure 23: Infected pupa with tongue
stretched across the cell

 

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