Chalk brood is a highly infectious disease of honeybee brood. Since first being identified here in 1993, it has spread rapidly throughout Australia. Losses to honey production have proved significant. Chalk brood cannot be effectively treated by the chemotherapeutic or comb sterilisation techniques often employed to treat other brood diseases.
The uncapping and removal of dead and diseased brood (hygienic behaviour) is a heritable behavioural trait of some honeybee strains. Hygienic behaviour is the primary mechanism of resistance to chalk brood and other brood diseases, such as American foulbrood. Hygienic colonies also have some resistance to infestation by the parasitic mite Varroa jacobsoni.