Interesting creature that looked like a hovering set of black & white striped legs at first. Only after it grabbed this stalk could I make out the body and wings.
Genus Bittacomorpha has 2 or several species depending on the source B. clavipes is common east of the Rockies and B. occidentalis along the Pacific Coast usually found in shady areas along wetlands flies late spring to early fall adults eat little if any flies with legs spread open the larvae are aquatic and feed on organic material, and breathe air at the surface