Nosema

Nosema is caused by the nosema apis microbe.

Age of brood affected

Adult bees, including workers, queens, and drones.

Infection method

Adult bees ingest nosema spores from:

  • contaminated food or water
  • food exchange with other bees
  • cleaning contaminated combs.

Symptoms

The following signs may indicate nosema infection:

  • bees unable to fly and crawling on the ground with their hind wings at an unusual angle
  • greasy abdomen
  • hives may be covered in faecal matter due to dysentery
  • dead bees at the hive entrance
  • reduced colony population.

Most symptoms of nosema apply to other diseases which makes diagnosis difficult.

Management

The following steps can reduce risk of nosema:

  1. Place hives in sunny areas, sheltered from cold, wind, and rain.
  2. Pack colonies in a small space for winter to keep them warmer and reduce colonies to single or 2-storey hives.
  3. Replace old, dark brood combs to reduce spores within the hive.
  4. Make high quality pollen available nearby to reduce any protein deficiency.
  5. Avoid stressing the colony from early autumn onwards.
To help control the losses from nosema:
  1. Provide appropriate nutrition.
  2. Place young queens in hives with large populations.
  3. Use new combs regularly.
  4. Place hives in dry, sunny locations.

Diagnosing nosema

Send 30 to the Apiary Unit for testing. These can be either:

  • sick bees
  • freshly dead bees from the hive entrance or top bars of the frame.

Place live bees in a cage, or jar with holes in the lid, and some queen candy. Dead bees can be sent frozen. Send samples to:

Apiary Unit
The Department of Primary Industries and Regions
33 Flemington Street
Glenside SA 5065
Page last reviewed: 20 Sep 2022

 


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