The Influence of Plant Species, Origin and Color of Garden Nursery Flowers on the Number and Composition of Pollinating Insect Visitors

Abstract

With recent publicized pollinator declines, citizens are becoming motivated to design gardens that support pollinators. As a result, garden centers have become a venue for advancing pollinator conservation, especially in urbanised areas. However, there is a paucity of evidence-based guidelines on what plant species or plant characteristics attract pollinators, especially native bees. Systematic surveys were conducted to identify what plants are most attractive to pollinating insects at a garden nursery (Zanthorrea Nursery) located in Western Australia. In the austral spring and summer of 2020/2021, each blooming plant species for sale was observed and all insect visitors were recorded over a 200-sec observation period. A diversity of native bees was recorded, however, the introduced Apis mellifera L. dominated. Of the 181 plant species present, less than half received visitors, and plant species varied greatly in their attractiveness to different insect taxa. Greater abundance of a plant species positively influenced visitation. Native bees preferred native flora, whereas honeybees preferred both native and horticultural varieties. The ten most visited plants by all insects were identified; three of these (Melaleuca lanceolata, Boronia crenulata, and Babingtonia virgata) were also most visited by native bees. Bipartite plant-pollinator networks revealed that resource overlapped and potential for competition varied among insect taxa and months. This study indicated clear preferences by insects among garden plant species offered at nurseries, and visited plants, especially those by native bees, should be promoted, and planted in larger abundances. Similar surveys can be used to identify “pollinator friendly” flora for the public.