Insect visitors to the Guelder Rose, Viburnum opulus var. opulus (Caprifoliaceae), in London, Ontario

Insects were observed at and collected from inflorescences of Guelder Rose, Viburnum opulus var. opulus L., in an effort to determine the effectiveness of the pollination behavior of different insects. Abundance, relative size of pollen loads, length of visit, and proportion of pollen load belonging to V. opulus var. opulus were recorded. Forty-nine species of insects were collected, ranging across five orders. Hoverflies (Syrphidae) and native solitary bees (Halictidae and Andrenidae) were the families most represented. Pollen samples taken from most of these insects contained a majority of pollen grains from V. opulus var. opulus (80%).