"Our Painted Lady caterpillars made chrysalises yesterday. Today one of them was wiggling like crazy for a little more than a minute. Could you tell us why?"
Many butterfly and moth chrysalises (pupae) wriggle in response to touch or movement. It is assumed that this is a natural instinctive response that discourages predators and parasitoids.
Some butterfly chrysalises do not have a jointed abdominal segment. Monarch and Queen chrysalises are not jointed and cannot move. Species that are jointed often move.
Click here to see Painted Lady chrysalises wiggle, hundreds of them! Other butterfly species like Julia, Gulf Fritillary, Tawny Emperor, Hackberry Emperor, American Lady, and especially Red Admiral chrysalises are extremely active when touched by anything. A Red Admiral chrysalis that has been laid on a table will often wiggle for minutes, often working itself off the table and falling to the floor.
People often think that this wiggling is a sign that that the adult butterfly is about to emerge. This is is an understandable misconception.
If you are in an area of the world where you can raise Julia butterflies, listen to their chrysalises when they move. They squeak!