Fooled You (changing color Spotted Jay)
Caring for caterpillars is a fascinating way to learn about the life cycle of lepidopterans (butterflies). Sometime ago, I saw some cute chocolate colored caterpillars. I collected them along with lots of the leaves they were eating. Placing them in a secure container, I put them in a cool place. Each morning and evening I cleaned their containers and gave them fresh leaves, the kind they like to eat. They happily ate and grew very fast. Two days later I opened the container and became very upset. Instead of chocolate colored caterpillars there were green caterpillars. I thought somebody had taken my chocolate caterpillars and replaced them with green caterpillars. I carefully studied the container and found chocolate colored skins in the bottom of the container. What had happened?
Caterpillars do three things, eat, change their skin, rest and then repeat the cycle. Caterpillars eat so much and grow so fast that they may more than double their weight every day. Because their skin can only stretch a certain amount this rapid growth creates a problem. To keep growing they must shed their old skin and replace it with a new one. As their old skin gets more and more stretched, a new skin grows beneath the old. At the right time, which they are programmed to know, they stop eating and spin some silk to stitch their old skin to a solid surface. Then they start to stretch their muscles in such a way as to split their old skin just behind their head. Then the caterpillar wriggles out of their old skin and walks away from it, dressed in a soft new skin. You may not believe this but they also shed the skin of their head, mouth and eyes as well.
The caterpillar has some special organs for making silk and spinning it. It knows it must use this silk to attach it’s skin to something solid, otherwise it would not be able to wriggle out of the old skin. God not only gave it the ability to make silk but also the knowledge to use it.
When the caterpillar emerges from it’s old skin, the new skin is soft and the head and eyes are swollen and soft. The caterpillar knows that it can not eat at this time. It must wait for its eyes and mouth parts to dry and harden, only then will it go back to eating.
As a caterpillar grows so fast, it may shed it’s skin four or five times before it is fully grown. Each time it sheds it skin it looks a little different or sometimes very different from before. My chocolate caterpillars had two chocolate colored skins before changing to green colored skins. No body had taken my caterpillars, they changed their skin color. The leaves their mother laid her eggs on were very young leaves that were a darker color. As the leaves grew they changed to a bright green color. My caterpillars had been designed so that when they were babies, they blended with the color of the leaf. As the leaf got greener, they changed the color of their skin so that they would still blend with the leaf. By blending with the color of the leaf they were less likely to be spotted by caterpillar eating birds.
My chocolate caterpillars later turned into Common Jay butterflies. God designed them with ability to change their skin color so that they would have a better chance of surviving in a world of hungry predators.