Overnight this caterpillar molted for the third time and is now a 4th instar larva of the Cecropia moth.

The most noticeable changes in appearance are the loss of any spots on the skin, and the variation in the color of the spicules (the spiky projections along the body). Up til now all of the caterpillar’s spicules have been a uniform shiny black. Now the two rows along the dorsal surface are yellow while the lateral spicules remain black.

The caterpillar’s skin is a beautiful shade of pastel green and blue.