Sunday, June 23, 2013

Monarch Caterpillar Prepares to Become Chrysalis

 To become an adult butterfly the Monarch caterpillar must go through complete metamorphosis.  Which means it needs to go through a pupal stage to emerge as a butterfly. 

This Monarch caterpillar is preparing to become a chrysalis, its pupal stage.  First it creates a silk "button" to securely attach itself to as it goes through the very inactive chrysalis period.
 It makes the "button" with the silk threads that come from its mouth.  This process takes about an hour, as it weaves threads all around the plant stem to secure the "button" in place.
 Once finished the caterpillar turns its body around and attaches the last pair of pro-legs to the button.  It seems to be a bit like velcro.
Here the little hairs on the pro-legs can be seen.  The caterpillar wiggles this around until it is satisfied that it is attached properly.

Now the caterpillar quiets down for a few minutes, and then slowly begins to let all its true and false or pro legs loose from the plant stem.
 Here you can see that the caterpillar is only holding on with one pair of its pro-legs. 

It very slowly lets its body down and then lets loose with this last leg hold.
Now the caterpillar is in what is called the "J" form or position. 

It will stay in this position for about 18 hours while its internal body makes significant changes. 

This is its last act as a caterpillar.  At the end of the 18 hours, its skin will split and a beautiful chrysalis will be revealed.

The next post will show that process.

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