Sacbrood Virus

Sacbrood virus (SBV) is a viral disease of honey bees which is caused by Morator aetotulas). Sacbrood is rarely considered a serious threat, however recent estimates suggest that one larva killed by the sacbrood virus contains enough virus to kill over one million larvae. It occurs when colonies have been under stress. Bees generally clear up the disease and remove affected brood themselves.

In Asia, there are two manifestations of the disease---occurring in the honey bee (Apis mellifera) and the Asian hive bee (A. cerana). Research indicates that nurse bees act as vectors of the disease, and the larvae are infected via brood-food gland secretions of worker bees.

Transmission

It is unknown how the virus is actually transmitted to the larvae in nature, why severe outbreaks occur only during the build-up season, or how the virus persists from year to year.

Symptoms

  • Infected larva die and the tissue disintegrates into a brown watery solution held by the larval outer skin
  • The skin sac can be removed intact from the cell
  • Cell is often uncapped but may also be closed
  • Cap is punctured
  • Non-pupated pale yellow larvae, stretched on their backs with heads lifted up towards the cell opening, trapped in the unshed, saclike larval skin containing a clear, yellow-brown liquid

Cause

  • virus - morator aetotulas

Diagnosis

  • Clinical signs

Treatment


  • Colonies often don't require any treatment, and will recover from the infection on their own.
  • Comb replacement and requeening

Prevention

  • Good sanitation practices

Article Reference

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