Viruses are pieces of genetic material that parasitize a host cell, making the cell produce more viruses. No vaccines or medications are available for any of the honey bee viruses. Therefore, good sanitation practices are the key to prevention. Comb replacement and requeening are the best practical responses to a virus infection.

Beekeepers rarely consider sacbrood a serious threat, however recent estimates suggest that one larva killed by the sacbrood virus contains enough virus to kill over one million larvae.

More research needs to be conducted on the sacbrood virus since 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 of sacbrood are partially uncapped cells scattered about the frame or capped cells that remain sealed after others have emerged. Diseased individuals inside cells will have characteristically darkened heads which curl upward. The dead prepupa resembles a slipper inside the cell. Diseased prepupae fail to pupate and turn from pearl white to pale yellow to light brown and finally, dark brown. The skin is flaccid and the body watery. The dark brown individual becomes a wrinkled, brittle scale that is easily removed from the cells (unlike AFB).

Honey Bee Disorders / UGA Honey Bee Program / UGA Entomology Department