Discover the secret codes of the caterpillar

Of all the crawling creatures known to man that go through the amazing process of metamorphosis, caterpillars are the ones that most capture my imagination. Unfortunately because they are so common there is a degree of contempt for the caterpillar which is regarded by some as a garden pest. 

Caterpillars emerge from eggs laid at a suitable feeding site. The first thing they eat is the egg and after that they munch their way through leaves at a fast rate.  They soon outgrow their skins and shed them several times until their bodies fail to produce a ‘juvenile hormone’ and instead of growing old gracefully they simply shed their last skin which turns into a chrysalis encasing them for an amazing transformation into a butterfly. 

The fact that caterpillars should do this at all is quite amazing in itself.  After all they were enjoying the good life, plenty of greenery around, great camouflage. They could have just eaten and slept and changed skins ad infinitum.

The chrysalis hides the mystery of the transformation from curious eyes no longer. We have dissected, put under the microscope and discovered the caterpillar’s secret agents.  They are undeveloped cells which it has carried around throughout all its moultings called imaginal discs.  Once the caterpillar pupates the imaginal discs start to develop.  These cells have the responsibility to change a caterpillar into a butterfly.

But before they can do this they encounter problems as the immune system of the caterpillar does not welcome their invasion and attacks the imaginal discs.  However the discs develop very quickly and soon overcome the immune system of the caterpillar and then the revolution begins in earnest. 

The imaginal discs  carry a coded image of legs, wings, antennae – the complete butterfly blueprint  - and over a period of  10-12 days the process of change is effected as they multiply and join together to complete the caterpillar’s metamorphosis.  

When the job is done the chrysalis splits and a damp butterfly emerges, it needs a little time to acclimatise, to dry out and to pump fluid into its wings.   There is no resemblance to the creature it was.  It has jointed legs and can no longer eat leaves, the emerging butterfly will only drink because its mouth has been replaced with a long proboscis which uncurls to reach into flowers for nectar.  Soon it will fly away to discover a new world, and new tastes,it will part of the pollination process.  In a few short weeks it will lay its eggs and the cycle will begin again.

The creature that could only crawl and munch has become a beautiful insect that flitters and flies and feeds on nectar.  Imagine, if you can, that you had no idea of the end result, that you had no idea where a butterfly came from until it emerged from the chrysalis.  It would take your breath away.  You might say that Nature or evolution was amazing. 

I wouldn’t credit this transformation to either.  I would see design in this process and in design I would give credit to the Great Designer and I would call Him God.