This is a much more typical color variant of M. pectinata than photo 202336. Macrosiagon fernalda is known from a fairly small area in southern California centered around Palm Springs- it may get into far western Arizona, but not this location. Besides, M. fernalda has fairly consistent coloration with the elytra entirely reddish-yellow, among other differences.

If any of you bugguiders out there have the ability to pop a ripiphorid (any ripiphorid!) in 95% ethanol after photographing it, I'd be mighty interested! I'd love to have enough material to start doing some genetic work on these guys to better define the species boundaries...