
The researchers placed honey bee and bumble bee colonies next to strawberry fields in the Göttingen and Kassel region and collected pollen from returning honey bees and bumble bees. The bees collect the protein-rich pollen mainly for feeding their offspring. The pollen DNA was investigated working closely with the Division of Molecular Biology of Livestock and molecular Diagnostics at the University of Göttingen, and the Department of Biochemistry/Molecular Biology of the Mittweida University of Applied Sciences. "DNA analysis tells us which plant species the bees have visited and how diverse their foraging behaviour is. To do this, we sequenced the DNA of the pollen and compared the sequences using a database of regional plant species," says Dr Svenja Bänsch, post-doctoral researcher in Functional Agrobiodiversity at the University of Göttingen.
"Our study shows that honey bees and bumble bees use very different plants to source their pollen in the landscape. In particular, the wide range of bumble bee nutrition, which they find mainly in flower-rich habitats, should be taken into account when taking steps to improve nature conservation. Both honey bees and bumble bees, whose colonies can be purchased or rented, are suitable pollinators in strawberry cultivation. However, naturally occurring wild bees should be encouraged as a priority," concludes Professor Catrin Westphal, Head of Functional Agrobiodiversity at the University of Göttingen.
Original publication: Bänsch S., Tscharntke T., Wünschiers R., Netter L., Brenig B., Gabriel, D. & Westphal, C. (2020) Using ITS2 metabarcoding and microscopy to analyse shifts in pollen diets of honey bees and bumble bees along a mass-flowering crop gradient. Molecular Ecology.