Natural populations of honey bees have been severely affected by the activities of humans (6). Non-native subspecies have been widely introduced to many areas of Europe, and managed colonies have often interbred with native bees, causing a loss of unique genetic diversity in local populations (6). In Germany the native race Apis mellifera mellifera is now thought to be extinct, as it has been completely replaced by the introduced Apis mellifera carnica (6).
A more recent threat to the species in Britain is the mite Varroa jacobsoni, which is devastating honey bee populations around the world (4) and was first found in Britain in 1992. These mites attack larvae, pupae and adults (3) and are very expensive to control; in the last 15 years the expense involved has caused a worrying 40-45 % of beekeepers to abandon the craft. To make matters worse, strains of the mite with resistance to the chemicals used in their control have recently been found (4).