Sacbrood Virus (SBV)
SBV was first identified in 1913. It is a member of the iflaviridae family and is fairly commonly seen in one or two cells within a hive.

It infects the larvae which die and fail to pupate. The larvae is contained in a watery bag and takes on the shape of a banana or gondola. The larvae turn light brown and then dark brown and can be easily removed intact from the cell. Fluid accumulates between the larva and larval sac. It is advisable to use forecps to remove the sac intact as it contains infectious matter.

If they are left the bees will uncap the cells and the affected larvae will gradually dry out

A severe sacbrood virus outbreak in a honeybee (Apis mellifera L.) colony: a case report
Scientific Beekeeping