Protoplasa vanduzeei (formerly Protanyderus vanduzeei) was collected just once, a male found in "Los Cerritos", California on September 14, 1915 by a Mr. Millard C. VanDuzee, who was an authority on dolichopodids at the time. The species is smaller than the other Californian tanyderid, Protoplasa vipio, measuring just 5 mm (versus 10mm). The two have starkly different wing patterning, with P. vanduzeei having the costal cell fully pigmented, among other differences.

The recent revision of this family places the type locality at El Cerrito, outside of San Francisco. There's also a Los Cerritos south of Los Angeles that could be a plausible location. Both areas were collected by VanDuzee, and I'm not sure how the author has distinguished which is the actual type locality in this case. But in either instance, these locations are now drastically altered and unlikely to still retain a population of this species. Perhaps in some remote stream of California it still survives. Adults are small and short-lived and could easily escape notice. This is the Ivory-billed Woodpecker of flies. It might be extinct or near to it, or perhaps we are simply poor at finding it, though, given its ostentatious wings, that seems unlikely.

Alexander, C.P. 1918 New species of crane-flies from California (Dip.). Entomological News, 29, 285–288.

Madriz Villanueva, Ruben Isai, "The primitive crane flies (Diptera: Tanyderidae)" (2017). Graduate Theses and Dissertations. 16173.

Williams, I.W., 1933. The external morphology of the primitive tanyderid dipteron Protoplasa fitchii OS, with notes on the other Tanyderidae. Journal of the New York Entomological Society, 41(1/2), pp.1-35.