Data from: Seasonal progression and differences in major floral resource use by bees and hoverflies in a diverse horticultural and agricultural landscape revealed by DNA metabarcoding

Gardens are important habitats for pollinators, providing floral resources
and nesting sites. There are high levels of public support for growing
‘pollinator-friendly’ plants but whilst plant recommendation lists are
available, they are usually inconsistent, poorly supported by scientific
research and target a narrow group of pollinators. In order to supply the
most appropriate resources, there is a clear need to understand foraging
preferences, for a range of pollinators, across the season within
horticultural landscapes. Using an innovative DNA metabarcoding approach,
we investigated foraging preferences of four groups of pollinators in a
large and diverse, horticultural, and agricultural landscape, across the
flowering season and over two years, significantly improving on the
spatial and temporal scale that can be achieved using observational
studies. Bumblebees, honeybees, non-corbiculate bees, and hoverflies
visited 191 plant taxa. Overall floral resources were shared between the
different types of pollinators, but significant differences were seen
between the plants used most abundantly by bees (Hymenoptera) and
hoverflies (Diptera). Floral resource use by pollinators is strongly
associated with seasonal changes in flowering plants, with pollinators
relying on dominant plants found within each season, with preferences
consistent across both years. The plants identified were categorised
according to their native status to investigate the value of native and
non-native plants. The majority of floral resources used were of native
and near-native origin, but the proportion of horticultural and
naturalised plants increased during late summer and autumn. Synthesis and
applications: We recommend that plant lists should distinguish between
bees and hoverflies and provide evidence-based floral recommendations
throughout the year that include native as well as non-native plants for
use in the UK and Northern Europe. Specific management recommendations
include reducing mowing to encourage plants such as dandelion Taraxacum
officinale, buttercups Ranunculus spp., and reducing scrub management to
encourage bramble Rubus fruticosus.