| American foulbrood |
Normal cell cappings, sunken dark, perforated cappings, or cappings completely removed |
Prepupae or young pupae |
Off white, then coffee brown, then black. Even coloured. Lose segmented outline |
Smooth rope 10-30mm. Elastic thread “snap back” when breaks. Difficult to remove larval remains |
Like dead fish |
On bottom side of cell, hard to remove, pupal tongue can often be seen |
| Sacbrood |
Cappings same as AFB |
Prepupae only |
Grey or yelow then brown, sometimes with a grey or black head. Segmented outline present |
Plastic sac, watery contents of sac often lumpy. Sometimes ropes to small extent. Prepupae easily removed from the cell |
Slightly sour |
Dark brown, easily removed in one piece. No tongue but prepupal head may be curled up. Scales not common, except in severe infections |
| Chalkbood |
Cappings same as AFB |
Prepupae only |
White (often with a yellow head), or black |
Soft, furry, filling cells, hexagonal shape. Later shrinking to hard chalky mummies |
Not noticeable |
White or black, hard, easily removed mummies |
| Parasitic mite syndrome |
Cappings same as AFB |
Older larvae and prepupae (not pupae) |
White, grey or yellow. Dried remains may be orange |
Watery, pasty; does not rope; dries to scale. Presence of varroa sometimes observed |
Sometimes sour urine-like |
Twisted up the wall of the cell. Sometimes curled around the entrance. Easily removed from cell. No tongue present |
| Half-moon syndrome |
Cappings same as AFB. Multiple eggs in cells, eggs attached in chains, and sometimes drone brood in worker cells |
Young larvae to older sealed larva |
Off white to dark brown. Trachea may be seen as dark lines in larvae |
Watery, pasty; does not rope |
Sour urine-like |
Twisted up the wall of the cell. Sometimes curled around the entrance. Easiliy removed from cell. No tongue present |