Platycheirus trichopus, also known as the western forest sedgesitter, is a species of syrphid fly in the Bacchini tribe of the Syrphidae family. This flower fly is typically found west of the Rocky Mountains in North America.[1] Most Platycheirus species cannot be identified past genus without microscopic examination, but according to Even Dankowicz, P. trichopus has a unique set of characteristics that make it an exception when/where high quality images of the head/face are available.