Shortly after arriving for another day at the visitor centre this morning, I began doing the rounds, checking all the creatures were alright. I was so excited when I noticed this Peacock Butterfly caterpillar beginning its transformation into a chrysalis, having missed the other 5 or so. For the next 8 minutes (9.38 am -9.46 am) I keenly watched the fat caterpillar get shorter and shorter, squashing itself into its shiny green tent. I have captured the action in this sequence of photos as best I could amongst a maze of fellow chrysalises! The final stage was for the hard worked caterpillar to decapitate itself (almost). You will see this in a video to follow.
|9.44am: It looked like a real struggle!
|9.46am: Once the major transformation was complete, there was much writhing, squirming and twitching. The chrysalis gradually darkened to brown.
The 'Big Question' in July's BBC Wildlife Magazine is all about how a caterpillar turns into a butterfly. In my reading, I have discovered that a caterpillar's juvenile hormone 'slows progress towards adulthood', keeping it a larva while the hormone's levels are high. Gradually the juvenile hormone slows down and falls below a critical level, triggering the final moult into a chrysalis. Inside the chrysalis, the caterpillar is basically recycled, and adult features finally develop!