Stonebrood

 

Causal agent

Aspergillus fumigatus a fungus. Other Aspergillus spp may be identified.

Age group

Egg

Larvae

Pupae

Adult - worker

Drone

Queen

No

Yes

 

 

 

 

Clinical signs

Outside

No signs

Odour

No odour

Larvae appearance

Larvae develop a collar like ring near their head

The larvae die and become black and extremely hard

Eventually the fungus erupts and forms a false skin which is white

Scales (larvae)

Mummified remains

Infectivity

 

Larvae ingest spores from the honey

The problem occurs predominately in immunocompromised bees

Transmission

 

Spores are in the environment

Post-mortem Lesions

 

Appearance of larvae

Diagnosis

 

Appearance of larvae

Culture

 

Wet mount of larvae with ring around neck shows mucelia penetrating throughout the insect.

Treatment

 

Improve hive ventilation, hygiene and general hive health

Common differentials

 

 

Zoonosis

Aspergillus can infect man causing severe respiratory problems