Fly ovipositing in antlion cone - Brachystoma
Pit 4 Reach of the Pit River near Big Bend, Shasta County, California, USA
June 22, 2018
Size: 2-4 mm
Observed this fly landing and apparently ovipositing in antlion cones. She had a somewhat bulbous posterior part of her abdomen that she wiggled and stirred around in the sand at the upper part of the antlion cone.