Small areas of wildflower grassland in urban areas support significant species richness and abundance of pollinating insects

Abstract

1. Diversity of invertebrate pollinators is essential in supporting flowering plant species richness, including agricultural crops. In the UK, losses are reported for bees, hoverflies, butterflies and moths. Urban green spaces are essential refugia for these groups, and restoration of these areas can improve pollinator diversity through improved floral resources.<br/> 2. Our research aimed to compare two differently managed areas of urban amenity grassland for their insect pollinators, with transect surveys of butterflies, bumblebees, solitary bees and hoverflies.<br/> 3. Our results revealed that even in an urban matrix, a small area of wildflower meadow had significantly higher insect abundance and species richness than a comparable amenity grassland. Both abundance and species richness of pollinating insects was positively related to floral species richness.<br/> 4. The wildflower grassland supported a number of notable solitary bee species and numerous hoverflies, although visitation by solitary bees was confined to only a small number of flowering plants, exhibiting visitation specialisation; however many of these plant species were not visited by other taxa.