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