The fields of the North Pennines were cut for hay a while ago, but these grassy strips hold late-flowering plants – knapweed, scabious, betony – with nectar for bumblebees and butterflies.
Similarly, all but two of the bees made between six and eight geranium visits before deciding to take a chance with the lavender-scented ones.As the researchers report in the July issue of Behavioural Ecology and Sociobiology, the social information gained from the colony seemed to play only a minor role in determining how quickly bumblebees switched to the lavender food source.
Now the Bumblebee Conservation Trust thinks it has worked out how to do it.The key, according to recent work by Jaromir Cizek, a Czech bumblebee enthusiast, is to feed the queens a high-quality mix of nectar and pollen freshly collected by bumblebees, not the low-grade stuff tolerated by their close relatives, the domesticated honeybee.
Reintroduction has been mooted before, but bees are prone to lethal jet-lag and long-tongued bumblebees are hard to breed in captivity.
New research shows that when a tasty source of food is available the hive mentality is blatantly ignored.The discovery was made when Ellouise Leadbeater, then of the Zoological Society of London, and Claire Florent of University College London were studying how bumblebees gathered nectar.
That compared with a figure of 60% for bumblebees that came from a colony where the scent of lavender was absent.Precisely why the bumblebees largely ignored social information about lavender and so steadfastly stuck with their personal knowledge about geraniums providing a bigger feast, even when it was no longer so, proved vexing.
For those who like to think of bumblebees as the gentle cousins to other, more waspish varieties, the news of their criminal behaviour may come as a disappointment.
It has been known for some time, for example, that Eristalis intricarius and Volucella pellucens, two European species of hoverfly that are poor mimics of bumblebees in general, and do not resemble any particular species, are widespread and common.
They painstakingly recorded the sites of robbery holes in yellow-rattle flowers, and studied the behaviour of 168 bumblebees.
If the bumblebees came from the lavender-scented colony, then once they had visited their first lavender plant, 80% of the flowers they subsequently visited were lavender.
Bumblebees are less studied than their honeybee cousins, but they also pollinate many commonly eaten crops, including strawberries, raspberries and runner beans.The two researchers and their colleagues raised 75 bumblebee colonies in their laboratory.
