happy bee

American Foulbrood (AFB)

AFB is caused by a spore-forming bacterium and it will kill a hive. It comes into the hive from nearby colony through bees either drifting or robbing and beekeepers through infected beekeeping tools/equipment and movement of infected combs. Infection starts when spores on the nurse bee’s mouthparts are spread to larvae when feeding the developing brood. These spores start germinating in the larvae’s gut and invading its body through the gut wall, eventually killing it at the pre-pupal or pupal stage.

How to recognise

Classic symptoms are:

  • Cell capping colour – instead of being light to dark brown infected cappings become black
  • Holes in cell capping as worker bees have identified a problem and removed the larva
  • Spotty brood pattern because healthy larvae have emerged all around it
  • Colour of brood – instead of being healthy pearly white, infected larvae and pupae turn brown like coffee and milk
  • Shape of brood and position in cell– instead of being plumb, infected larvae and pupae slump to the lower wall of the cell
  • Pupal tongue – you can sometimes see the dried remains of the tongue pointing directly across the face of the cell


All hives with AFB must be destroyed by burning.  


Do the course

We recommend you do an AFB course run by American Foulbrood National Pest Management Plan (AFNPMP), even if you use a Disease Elimination Conformity Agreement (DECA) inspector for your annual and legally required AFB hive inspections. Here is a link to their courses.

Read the book

We recommend you read ‘Elimination of American Foulbrood Disease without the use of drugs’ by Mark Goodwin. This book is available from our library.