Sacbrood Virus

 

Causal agent

Morator aetatulas

Age group

Egg

Larvae

Pupae

Adult - worker

Drone

Queen

No

No

 

 

 

 

Clinical signs

Outside

None

Odour

None

Brood

Few abnormal cells

Cappings

Almost no torn cappings.   Scattered cells.

Larvae appearance

Larvae dies just before pupation – upright in cell – so normally in capped cell

Head development retarded and head darker than the rest of the body

Larvae colour is pearly white to gray and finally black.

When larvae removed from the cell, often appear to be in a sac filled with water

Scales (larvae)

Grey, brown and brittle, loose in cell, slipper shaped

 

 

Sacbrood larvae removed from cell

“Chinese slipper”

Other

Often seen in association with Chalkbrood - Ascosphaera apis

Infectivity

 

Virus mildly pathogen and not resistant

Transmission

 

 

Post-mortem Lesions

 

Retarded head development

Diagnosis

 

Appearance of larvae

Treatment

 

Spontaneous recovery – especially when nectar flows are strong

Note concentration of hives in an area

Re-queen hive

Regular and routine brood comb changes – 3 frames per year per super

Common differentials

 

 

Zoonosis

None