The Eastern Catkin Fly (Brachypalpus oarus) is a large, infrequently-observed, Nearctic flower fly of old woodlands. Usually observed hovering near or perched on sunlit tree trunks. An imperfect mimic of large mining bees. When perched on a tree it resembles robber flies of the genus Laphria. The body is covered with long, yellowish hairs. The face of the female is triangular in shape. The larvae live in rot holes in deciduous trees. Length 10 – 14 mm.
Flight season: April – May
Similar species: Chalcosyrphus inarmatus