British bees are having to adapt to a different landscape and therefore a different diet to survive.

A team at the National Botanic Garden of Wales has documented seven decades of honey to discover how the contents have changed. They found a ‘profound change’ in the British landscape. The favorite 1952 diet of the honeybee was white clover, but now it is bramble and the invasive Himalayan balsam flower.

Researchers discovered that the reason behind this change is not a curious appetite for exotic flavors so much as the fact that native British wildflowers are in decline.

Dr. Natasha de Vere, conservationist and co-author of the study, and Dr. Laura Jones, lead author, used cutting-edge DNA barcoding with the team to identify which plants bees like to visit most often daily by checking pollen trapped in the honey.

This new study analyzed 441 honey samples from across the UK in 2017. They were compared to the 1952 survey where grains were analyzed by a microscope from hives around the country.

Researchers encourage people to grow more flower-rich hedgerows with bramble and plant grasslands with a rich array of wildflowers in order to help honeybee populations get a boost. Over the past sixty years of changing flora, some wildflowers have declined while others were introduced. It’s a different landscape now.

This unrelated 3:58-minute video Is Himalayan Balsam Bad? is by Eco Sapien:



Changes that have caused white clover to drop to second place as a honeybee staple include inorganic fertilizer used in farming, herbicides, and fewer pastures than there used to be.  

Some new favorite bee foods are apple, hawthorn, sycamore, maples, cherries, plums, and heather. Also oilseed rape, which is problematic since the seeds are treated with neonicotinoids, which are deadly pesticides for bees and are currently banned in the UK.

Dr. Jones found that white clover had reduced from 93 percent to 62 percent and was a major ingredient in only a third or less of the sampled honey. White clover decreased in the landscape by 13% between 1978 and 2007, according to the Countryside Survey for the UK.

In contrast, bramble appears in 73% of honey samples compared to only 58% in 1952. Oilseed rape, genus Brassica, was only 2% back in 1952 but was at 21% by 2017.

Himalayan balsam, Impatiens glandulifera, is a highly invasive species with beautiful orchid-like white, pink, and purple flowers. It grows along river and roadsides and was introduced to the UK in 1839. It is listed under Schedule 9 of the Wildlife and Countryside Act 1981, so it is an offense to plant it or cause it to grow wild. In 1952 it was only found in 1% of honey tested, now the conservative estimate is 15%.

When honeybees forage on Himalayan balsam their bodies are covered in a whitewash of pollen, causing them to be called ‘ghost bees.’

Researchers agree grasslands need to be improved, expanded, and planted with wildflowers. Planting more white clover for nectar for bees would be a step in the right direction. According to de Vere, abundant sources of nectar and pollen for high-quality food from diverse sources would help honeybees to thrive again.

The findings have been published in the journal Communications Biology.