Chilled Brood

Cause

Larvae in all stages are killed by exposure to low temperature.

Colonies approaching starvation have no carbohydrate reserve to produce heat.

Insufficient adult bees to cover the brood

Opening colonies for too long in low temperatures.

Signs in the colony

Brood of all stages is dead. This includes sealed brood.

The dead brood is usually at the periphery of the comb

Some of the capped cells may be perforated.

Larvae turn grey and then black but remain shiny.

Finally a black scale is formed which is removed by the bees.

Likely time for this to happen is in early spring when brood outnumbers adults, particularly if insufficient stores are present.

This may be seen following spray poisoning of the bees as many adults are lost.

Diagnosis

This is the only condition where open and sealed brood are equally affected. None of the brood diseases will do this.

The fact that the larvae remain shiny throughout is only seen in chilled brood

Treatment

None

It is usually the fault of the beekeeper either by not ensuring sufficient stores or to inappropriate examination.