They are eating my Chinese Lanterns so fast I am afraid they will have no leaves by tonight!
They're beetle larvae of some kind. Since this is physalis, the potato beetle comes to mind first. I'd like to see a better image of one of these little guys as these don't seem to be a dead ringer for that particular insect. However, CPB is a major pest for this plant.
In the meantime, flick into soapy water.