Friday, December 8, 2017

Luna Caterpillar Molting

Luna moth caterpillar molting - Linda Bower
One of the perks of volunteering with the Butterfly House is the opportunity to raise moths.  The caterpillars devour the leaves they've been given, and when their exoskeletons grow too tight they crawl out of their skin (molting), and emerge in a new stretchy outfit to grow into. They go through five instars (molts) until they finally form a pupa.

Most of us don't have the patience to watch the entire process and find only the old discarded skin (exuvia) if even that.  Linda Bower has saved us the time by filming this great action video of a luna moth caterpillar (Actias luna), molting.  You won't want to miss a single highlight so here is a viewer's guide.
  • It starts with closeup views of the head and mouth which opens briefly.
  • At 0:12 we see a full length view with its two hind prolegs attached to a silk pad.  The pale green head has emerged and its dark former face sits on top like a hat.
  • By 0:37 it starts to rapidly shimmy out of its old skin.
  • At 1:08 the old face skin is displaced, hanging on until 1:31 when it falls off.
  • At 2:00 - free at last!
By 2:32 the caterpillar turns around to eat the discarded exuvia, the first meal in its new clothes.  Energy is precious at this stage and there is no need to miss a free meal, even if it was the old hand-me-down exuvia.
Linda Bower is a member of our Master Naturalist chapter and a frequent contributor to the blog.  Her videos of a number of nature subjects are available at her Youtube channel, Nature in Motion.