Bugguide had only two images for this species before, of a single specimen captured by Jillian Cowles in or near Vail AZ. The shape of the terminal pair of wing spots is harder to make out in her photos and still not perfectly clear in mine either. Williston's original description and illustration of a single female from New Mexico (as available in scanned form on Biodiversity Heritage Library ) doesn't perfectly match the shape of the terminal and midwing spots on the specimens from Oliver Lee MSP, and he didn't show the cleft shape of the subterminal article of the metatarsus that is visible here in the shot with dorsal view. Neither may be significant, as the silhouette of the tarsal articles changes with angle of view and there definitely were variations in the darkness/outline of the wing spots among other OLMPS individuals that eluded me - plus the scanning may have bleached out some of the spots' edges in Williston's drawing.

There were dozens of this species around in OLMPS, and they discreetly and timidly showed up only at the small number of Ziziphus obtusifolia aka Lotebush that were flowering in dappled shade in or next to the arroyo. The single tall and compact Z. obtusifolia in the parking lot had a few too, though not nearly as many as the more horizontally sprawling Lotebush down in the arroyo.

These past 2 weeks I've also seen them on the few flowering individuals of the same shrub species in Dripping Springs and Soledad Canyon, on the west side of Organ Mts in Doña Ana Cty. There are very few flowering plants of any kind around this June, but I haven't seen the fly anywhere on or near any other flowers.

Nausigaster unimaculatus is equally abundant on those same few Lotebush specimens with abundant flowers in the same places, along with a relative frenzy (at least for a very dry year) of other small pollinators. At 100F temperatures none of them cooperated, to the point where catching more than one camera angle of the same individual was all but impossible. The one shown here is just about the only one that didn't immediately take off before or at my first click, or didn't change its position at all and sipped just a single flower, or insisted on hiding its colors in the shaded underside of leaves & branches - among dozens I tried to sneak up on, over several days and in all of the above places. Almost any other insect flying close by caused them to take off promptly as well.