Fig 1.
Examples of plants hosted in the GBG and native pollinators visiting them.
a) Centranthus ruber (L.) DC (native, funnel) and Apis mellifera L; b) Teucrium fruticans L. (native, bilabiate) and Xylocopa violacea (L.); c) Echinops sphaerocephalus L. (exotic, head) and Apis mellifera; d) Eschscholzia californica L. (exotic, disk) and Lasioglossum sp.
Fig 2.
Native (n = 73; A) and exotic (n = 59; B) plant–pollinator networks. Bars on the left side represent plants, grouped according to flower morphologies; bars on the right side represent bees, at species level when possible. An indication of the family to which bees belong is reported on the extreme right side of each plot, after bee (genus/species) name. Linkage width indicates the number of individuals of that bee species paying visits to plants with given flower morphology. The length of the bars for plant species represents the frequency of species with a given flower morphology. The length of the bars for the bee species represents the total number of individuals recorded for that species on all plant species combined.
Table 1.
Selected existing literature on the five Salvia species considered in this study.
We are reporting studies indicating pollinator visits actually observed by authors.
Fig 3.
Average number of visits per patch record on the five sages.
Upper part of the graph report bee families observed on each Salvia species. Bee assemblages (Apidae are split in three subgroups, being the most common and easy to recognise) is addressed by green spots indicating presence on flowers. On the lower graph, error bars are represented with 95% confidence interval. Flowers of each species may be appreciated in the photos on top. In that of S. verticillata, a honeybee (Apis mellifera) is collecting nectar. Photo credits: M. Giovanetti and D. Lupi.