>While feral honeybee colonies – usually created by swarms of non-native bees that have left a nearby managed hive – are occasionally found in the UK, there was no evidence that self-sustaining colonies of native, tree-nesting honeybees still existed in England, and no record of the wild subspecies living in Blenheim.
>Filipe Salbany, a bee conservationist who found 50 colonies of the rare honeybees in Blenheim’s 400-acre estate, said: “These bees are quite unique in that they live in nests in very small cavities, as bees have for millions of years, and they have the ability to live with disease. They have had no treatment for the varroa mite – yet they’re not dying off.”
>The varroa mite, a parasite that feeds on and attacks honeybees, arrived in Britain in 1992 and decimated the UK’s population. Salbany believes the bees he has found have evolved to survive. “We are not seeing the deaths we would expect to see with varroa.”
>Unusually, the bees swarm with multiple queens – up to nine in some cases – to ensure the colony’s survival, and have been recorded foraging for honeydew on the treetops in temperatures as low as 4C. Most bees will stop flying at 12C. “A wild bee that has adapted to the environment is called an ecotype, and this bee could be a very precious ecotype – the first wild bee that is completely adapted to living in the oak forest.”
>The results of DNA samples taken from the bees are expected within the next three to four weeks, but Salbany is confident it will show the bees are descendants of an ancient native species. “I think the majority of the genetics are going to be of an old English bee, of something that was here many, many years ago.”
>His preliminary analysis of the wings of the honeybees strongly suggests they are related to indigenous honeybees that once lived in Britain. “They are not from the imported stocks of bees that people bring in. The wings are smaller and their veins are very distinct.”
>The bees’ cubital index, a method for differentiating breeds of honeybees, also confirmed they are “more of an indigenous bee” than anything else, he said, but their adaptations have made them unique and peculiar, and they have very little banding. “Supposedly, wild tree-nesting honeybees which can sustain themselves do not exist, so nobody knows what type of wild, self-sustaining honeybee is actually left in the UK.”
>One of the nests he found was at least 200 years old and he estimates that the bees have been living on the Blenheim estate, which dates back to the middle ages, for “quite a few” centuries. Unusually, they have built their nests in tree cavities a quarter of the size of a normal beehive, 15 to 20 metres off the ground, and despite several ecological surveys over the years, “nobody knew they existed”. The entrances to the nests typically have a diameter of less than 5cm.