[gorbelly]

Well, it didn't respond positively to the copper fungicide, so I tried serenade. Almost all of the new growth on the vines appeared affected today, so I pulled the plant. Oddly, the plant right next to it, which had intertwined with it, remains totally unaffected. This makes me suspect it might have been CMV, which apparently does not spread easily without an insect vector, and M. scabra seems pretty uninteresting to everything except Japanese beetles.

Hoping it doesn't spread to the other mouse melon plants or to my tomatoes, squash, etc.

Although they get off to a slow start, once they get vining, they grow very quickly, so maybe there's time to plant another one and get some harvest off of that one before frost. And I suspect the slow start might not be so slow during the heat of summer vs. the cool and unpredictable weather of spring.

Thanks for your help anyway, BigVanVader.

EDITED TO ADD: It was a strange presentation, so maybe it wasn't CMV. It never managed to look like it was going to kill any of the foliage. And none of the foliage ever went significantly yellow, just mottled/dotted. Oh well. I suppose it's better to be safe than sorry.