During the last 20 years the Asian bee mite, Varroa jacobsoni, has become the major problem of beekeeping with Apis mellifera in Europe, the Middle East and North Africa. After infesting a honeybee colony, the mite population increases slowly but apparently without check over the next couple of years. In the third or fourth year damage caused by the mite, mainly during the reproductive phase within the sealed brood cell, leads to the development of 'crippled' workers and the subsequent breakdown of the colony. This happened to countless colonies and forced beekeepers to interfere to save their bees. Today in infested areas all colonies are treated at least once a year to reduce Varroa to a level which allows for surplus honey production.