Amoeba disease is a parasitic infection of the excretory organs of adult bees. It rarely occurs alone and is usually found alongside nosema.

The organ affected

The parasite establishes itself in the fine tubules responsible for excretion, which remove waste from the bee's body.

Once established it disrupts that function, and the accumulation of waste worsens the bee's general condition.

Signs

There is no distinguishing feature, and the picture closely resembles nosema:

• Crawling bees in front of the hive unable to fly
• A colony that fails to build up in spring
• Faecal marks
• Loss of adult bees

It therefore cannot be determined in the field; diagnosis requires microscopic examination.

The connection with nosema

The two are often found together in the same colony and reinforce one another.

The same conditions provoke both: damp, long periods without flying weather, unsuitable winter stores and stress.

In practice they need not be separated; the measures are the same.

Transmission

The resistant cyst stage spreads with faeces and persists in the comb. Bees cleaning the comb take it up.

Old comb therefore carries risk.

What to do

There is no specific treatment. The approach is to restore the conditions:

• Renew comb regularly. The most effective measure
• Reduce damp in the hive. Ventilation and a slight forward tilt
• Watch the winter stores. Honeydew honey burdens gut and excretion
• Provide clean water
• Keep the colony strong
• Requeen if weakness persists

Economic significance

On its own it rarely causes serious loss. Its importance lies in weakening the colony alongside nosema and other stressors.

The useful question is therefore not "which parasite" but which conditions are weakening the colony.