Chin’s Butterfly Gallery
The Baron (Euthalia aconthea) emerging from pupa (1). The Baron (Euthalia aconthea) emerging from pupa (2). The Baron (Euthalia aconthea) emerging from pupa (3).
The pupal case split and the fully developed butterfly emerged in the first moments of eclosure.
Watching the magical moments of metamorphosis
By Chin Fah Shin

IN MY VIEW, one of the most interesting natural phenomena that we can see in suburban greenery is metamorphosis, the development or growth of an insect from egg to larva, from larva to pupa, or chrysalis, and finally to the adult insect, or imago. What fascinates me is the emergence of the adult butterfly from the pupa stage.
  I have seen emerging butterflies many times. On every occasion, I have watched in awe. Every time a butterfly emerges, it seems to me that Mother Nature has worked her magic yet again to change a flightless, worm-like caterpillar into a winged and graceful creature which bears no resemblance at all to its earlier form.
  The transformation is so complete that people who did not know this aspect of insect biology would surely find it hard to believe that the caterpillar and butterfly are the same creature at different stages of development.
  One species that I have seen emerging is the Baron (Euthalia aconthea gurda), a member of the Nymphalidae family. With a wingspan of about 6cm, the Baron is a medium-sized butterfly. Its wings are coloured various shades of brown and marked with dark spots and rings and some white dabs.
  Soon after moving into my present home in a Kuala Lumpur suburb, I photographed a specimen that had "strayed" into my house. Later, I discovered that the larval food plant is mango (Mangifera). Some of my new neighbours grow this fruit tree in their compounds. So I had an inkling then that I would meet the Baron again.
  We too had planted a young mango tree on the roadside in front of our house not long after moving in. In 1993, I found a pupa and several empty pupal cases on this tree. I decided to "stake out" the remaining pupa, firstly to check out the identity of the species, and secondly to photograph the butterfly at the moment it emerges.
  In due course, the pupa "darkened" and I could see the butterfly's antennae and some of the wing patterns through the thin, translucent pupal case. It meant that the insect had fully developed and was ready to emerge.
  Sometime after mid-night, I began my vigil, with camera and electronic flash at the ready, waiting for that "magic moment" when the butterfly would emerge. There was a street lamp and I had switched on the light in my porch, so it was bright enough to see the pupa, which was suspended under a mango leaf.
  It was a hot and humid morning, and I soon got thirsty just waiting. Around 4.30am, I went inside the house for a drink of water. Unfortunately for me, the butterfly chose that time to emerge. So I missed the magic of that moment. I was away for only five minutes. When I returned, the creature was hanging to its pupal case, its wings already expanded but still wet and limp.
  All was not lost, however. I took some pictures of the newly emerged butterfly, from which I was able to identify the species as the Baron (Euthalia aconthea gurda). By about 9am, with its wings now completely dry, it took off into the morning sunshine toward a new life as an adult. And I went to bed. The following year, I found a caterpillar on the same mango tree. There was no doubt this time about the identity of the species. It
The Baron (Euthalia aconthea gurda).
This Baron (Euthalia aconthea) had just emerged from its pupal case.

Newly emerged Baron (Euthalia aconthea).
The pristine beauty of a newly emerged Baron (Euthalia aconthea).

had branched spines radiating from its green body and a yellow dorsal stripe running the full length of the body.
  A week after I had found it, the caterpillar turned into a pupa. The pupa's colour was green for about two weeks and then it began to darken. The red-tipped antennae and some of the wing patterns could be seen through the pupal skin, indicating that the butterfly’s time was near.
  Again I kept vigil through the morning. The second time around I was more fortunate and photographed the Baron as it was emerging. The first cracks appeared in the pupal case around 6am, and the butterfly pushed itself out head first. When it was completely out, it turned and held onto the pupa case with its crumpled and wet wings hanging limply.
  Then, with the wings held slightly apart, the butterfly began the laborious effort of pumping its body fluid into the veins in order to stretch them out. I kept watch until the butterfly was ready to fly. By about 9am, the Baron took off into the bright new day. And I went to bed, happy that I had at last got the photos that I had waited so long to take. The pictures on this page came from that series.
  There are some other common butterfly species found in my suburban neighbourhood that I have watched emerging. They are the Plain Tiger (Danaus chrysippus chrysippus), the Common Palmfly (Elymnias hypermnestra), the Lime Butterfly (Papilio demoleus malayanus), and the Common Mime (Chilasa clytia clytia).