Fly with abdomen strikingly lemon-yellow below, visiting flowers of Veronica anagallis-aquatica along shore of pond. Ruderal floodplain community with Kochia scoparia, Chenopodium simplex, Chenopodium berlandieri, Helianthus annuus, and Cleome serrulata. Mid-afternoon, sunny, 81 F to 85 F, light breeze. Very smoky afternoon with unhealthy air quality.

Elevation ca 4000 feet. Disturbed riparian corridor on stream restoration site within a patchwork of native and non-native grassland.

Keyed to genus in Miranda et al 2013. Field characters include the yellow markings on the thorax and dorsal patterning on the abdomen, yellow and black with paired medial black stripes on T3 and the more apical terga. Based on Vockeroth 1992, these species is readily distinguished from others in the genus by the continuous yellow margin of the abdomen (vs. alternately black and yellow in others). This is a female due to the black stripe on the frons (yellow without the stripe in males).