This series was photographed within an hour of dusk in desert scrub on the bajada below Henderson Canyon, near Borrego Springs, CA.

I'm fairly confident this fly is in the family Mythicomyiidae, based on its distinctive gestalt: "duck-bill"-like proboscis; globose head with V-shaped antennae; hump-backed thorax; and bloated-looking abdomen...pale-whitish below, with dark transverse markings at the anterior bases of the terga above. (I suspect the amount of "bloat" of the abdomen may depend on whether the individual is a gravid female or not).

It was visiting flowers of the inconspicuous desert thread-plant, Nemacladus rubescens, in the family Campanulaceae. Flowers in the genus Nemacladus often have a pair of strange digitate, translucent, rod-like processes attached at the base of the stamen tube (for example, see these images of N. rubescens, N. tenuis, and N. montanus). In the image above, the fly's right hind leg is on of these "rods". The other set of rods is visible to the right. The function of these rod-like processes seems to be unknown, but is likely related to pollination. Thus I was excited to get a series of images of a pollinator at work...although in this instance, I didn't discern any special interaction of the fly with the rod-like processes. Nevertheless, it's good to have recorded an insect associate of a Nemacladus, which was definitely interacting with both anthers and stigma of the flower.