Length: 6-8 mm
A study of insect visitors to Pasture Rose (Rosa carolina) in Maine showed that Bumblebees interfered in a small way with the foraging of Toxomerus geminatus. When a Bumblebee landed on a rose flower, T. geminatus left, as did another Syprhid fly, Melanostoma mellinum. The disruption to T. geminatus feeding was minimal, because T. geminatus hovered nearby until the bee moved on. The other Syrphid species, Melanostoma mellinum, saw its foraging time reduced by as much as 40 percent because it left the immediate area after being driven off by the bee.
Toxomerus geminatus ranges from Minnesota to Quebec, and south to Colorado and to Florida.
American Insects site