As a caterpillar, Murray had a green casing under his skin. He sheds the outer skin and reveals the green pupa, or chrysalis.
He is still stuck to the twig and will hang this way until adulthood. You can now see the cremaster which is the black spiny protrusion connecting the silk to the body of the pupa.
Unfortunately, I was away for the day and missed most of the transformation. We arrived at the last few minutes of Murray wriggling out of his skin. By the time I had the camera in position, the skin had dropped.
In the first photo, you can still see the soft ribbed body of the caterpillar. The pupa hardens within an hour or so after shedding.
This view of the pupa is the ventral side – you can see the wings (the butterfly is head down inside the casing). If you look carefully at the right lower edge of the pupa you can see gold dots – these are where the butterfly’s eyes are.
The next photo was taken about 1 1/2 hours after the first photo. Now the pupa is harder and shows the characteristic gold dots around part of the upper segment.