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!