Several sources have listed wild ginger as a larval foodplants for pipevine swallowtails. In over 25 years looking at this plant in the wild, I've never seen larvae on them. Has anyone seen them in this plant under circumstances that wandering larvae wouldn't explain?

It's an "alternative" food source, meaning swallowtail larvae will food on it if Aristolochia pipevines aren't readily available and/or larvae densities are very high (caterpillars become solitary as they grow larger). It's kinda like saying that woodpeckers feed on carrion: they'll make do if nothing else is available.

They both grow will here but there is WAY more wild ginger available. It's everywhere. Pipeline swallowtails are also everywhere... Just not much pipeline or at least as much as the numbers would suggest. That's why I've been keeping an eye on alternatives.