Prepupa kicks off the pupal stage for a ladybug. When the larvae are ready to move to the next stage of their ladybug lives, they attach themselves belly-first to a surface such as a plant leaf. Motion stops, and so does feeding. This is no time for wiggling.
The larva curls up a bit, and some of the larval skin may still be hanging around. The future beetle scrunches up to be more compact and begins to look less like a lizard and more like a ladybug. The pupa will change in color, possibly turner darker or more orange.
The pupal stage is a time of transition for a ladybug. To the casual observer, it just looks like a whole lot of waiting. The process lasts a week or so, ending when the silent, compact little mass makes its way out of its pupal skin.