Using pollen DNA metabarcoding to investigate the foraging preferences of honey bees

Abstract

Honey bees contribute to human wellbeing; through the use of honey, wax and propolis, and as the pollinator of both wild and crop plants. The increased rate of honey bee colony loss has caused worldwide concern, caused by the interacting effects of habitat loss and fragmentation, agrochemicals, pests and diseases, and climate change. DNA metabarcoding provides a tool for identifying the pollen in honey and therefore the plants the honey bees are foraging upon. The DNA is amplified using the rbcL marker using a two-step protocol and sequenced on the Illumina MiSeq platform. Sequences are compared to our Barcode UK reference library using BLAST. Using the National Botanic Garden of Wales as our study site, we recorded the plants in flower and at the same time sampled honey from hives in the Botanic Garden’s apiaries; one sited within the horticultural area and one sited within native habitat adjacent to a National Nature Reserve. Initial results for early season foraging in April and May showed that 437 genera of plants in flower were recorded in the study site but only 11% of these were used by the honey bees. Here we present the results of the honey DNA metabarcoding throughout the foraging season from May to September and compare it with the plant survey data to build a temporal and spatial picture of foraging for honey bees with access to a high UK floristic diversity. Having a detailed understanding of the habitat and foraging requirements of honey bees is required to fully understand declines and supply guidelines for suitable plants for healthy honey bee colonies.