Is this an error? Why is this stultana? Michael Sabourin does not see anything that would eliminate rostrana. I have made the correction at MPG but would like to know if I'm missing something.

Two things strike me about these taxa:

1. There is a perplexing diversity of patterns among the specimens purported to be "rostrana" at BOLD; and

2. Regarding P. nigrocervina, for a taxon that appears to be widely distributed in (at least) Texas and the Gulf Coast (see MPG map), there seems to be a dirth of photographs on MPG and BG.

Among my images, there is a consistent pattern among a set of small male Platynota's (FW length 7-8mm vs 9-10mm in rostrana) with a costal fold which is dark gray continuing around and over the thorax, creating an obvious dark "horse collar". These males have a fairly consistent pattern of corrugation on the forewings, unlike anything in (identified images of) rostrana and distinguishable from most/all platynota, for instance.

I don't have access to original descriptions of either species, but I'm going to go out on a limb and surmise that a lot of these smaller male Platynota's with the dark gray costal fold and collar are P. nigrocervina. This also implies that there may be some conflation of the two in (...gulp...) the BOLD system at the above link.

The usual caveat applies: I'm not a species expert; just a birder-turned-Moth-er who enjoys identification challenges like winter sparrows and fall warblers.

I think you are right. Especially after looking at my own photo of a much browner specimen from the Everglades. The pattern is there, and Janzen's specimens (at BOLD, from Costa Rica) appear to be a dead match.