Colony hygiene has two sides: the cleaning the bees do themselves and the cleaning the beekeeper does. The two complement each other.

The bees' hygienic behaviour

A healthy colony recognises diseased or dead brood, opens the cell and removes it. This is called hygienic behaviour and it is heritable.

Colonies showing strong hygienic behaviour:

• Are more resistant to chalkbrood and the foulbroods
• Partly limit Varroa reproduction
• Deal with problems before the beekeeper notices them

This trait can be measured and selected for; it is the most useful single indicator in breeding.

Comb renewal — the most important intervention

Old comb accumulates three things: disease agents, chemical residues and cocoons. The cells narrow over time.

Renewing a fixed proportion of the brood combs each year is the most effective hygiene measure a beekeeper can take.

The comb removed becomes a wax source; having foundation made from your own cappings wax also breaks the residue cycle.

The infection the beekeeper carries

Most infection is carried not by bees but by the beekeeper.

• Hive tool: The commonest route. American foulbrood spores survive on the surface and are not killed by alcohol. Flame or a soda solution is required
• Gloves: Leather gloves cannot be washed; a type that can be changed when soiled is more hygienic
• Moving comb: Passing frames around between colonies at random is the riskiest habit

Order inside the hive

• Match the space to the colony's strength. Space the bees cannot cover is an invitation to pests
• Control moisture. Ventilation, a forward tilt, raising the hive off the ground
• Watch the debris on the floor. What accumulates there tells you about the colony
• Seal cracks in the hive

Bringing in new colonies

A colony from outside should be kept apart, and its brood and mite level checked. Buying colonies, comb or honey from unknown sources is the riskiest thing a beekeeper can do.

A dead colony

When a collapsed colony is found the hive should be closed at once. A hive left open is robbed and the agent inside it is scattered through the whole apiary.

Do not give the comb to another colony before the cause is understood.

Summary

Hygiene is not a product but a set of habits: cleaning the tool, renewing comb, not moving frames at random and keeping records. All are cheap, and together they prevent the most expensive problems.