Pests: Varroa destructor
Varroa came into the UK in 1992. They are the number one threat to honey bees. They also spread viruses, for example the commonly experienced Deformed Wing Virus.

Females lay eggs in sealed brood, 1 male and 4-5 females, more in drone brood. The male hatches first and mates with each female at 7-8 days. When varroa are in a brood cell they feed by biting into the pupae. At this time the varroa inoculates the pupa with all the infectious matter it is carrying. for this reason it is important to have an efficient integrated pest management programme (IPM).

There is excellent free advice from Beebase the UK wide service on honey bee health and and the Honey Bee Health. Coalition in N America. Download from the book icons. Be aware different treatments are available in Europe and North America.

Also refer to the mindmap that illustrates integrated pest management.
Integrated Pest
Scientific Beekeeping
Oldest Varroa tolerant honey bee population provides insight into the origins of the global decline of honey bees
Sugar shaking to measure varroa levels.