SBV or Sacbrood Virus (Morator aetatulas) often appears during spring or colony buildup and causes larval death. The pupa fails to pupate and has a “shrunken head” appearance. When you see perforations in the sealed brood with the infected larvae inside, the perforation is usually choppy or jagged indicating a problem. If the SBV pupa is totally open, the capping has been completely removed by bees and the pupa is most likely greyish-yellow to brown and starting to dry out. When removed the pupa looks similar to a slipper or canoe. Infected adult bees will have decreased life spans.
• Perforated sealed brood, pupa present with undeveloped head.
• Color ranges from pearly white to pale yellow to brown and eventually to black, when it is in scale form it is brittle and easily removed.
The only known treatment is to re-queen.
SBV (Sacbrood Virus)