Cecropia Watch, Pt. 3

. . . I'd discovered something about these big moths when I found this one in my garden last year--a Modest Sphinx Moth. (Actually, it found ME. I looked down, and it was clinging to my leg.)  While not as big as a Cecropia, it was spectacular!  I pried it gently off my pant leg and was amazed that it clung so tightly.

While studying this moth, and doing research for Dark Emperor and Other Poems of the Night, I discovered that most moths are nocturnal and don't fly during the day. More importantly, when they first eclose, they just sit in one place and pump their wings until evening. 

Why all this clinging and pumping?


Well, as is beautifully documented on the website Bug Life Cycles, the Cecropia begins its life as a tiny egg, attached to the leaves of certain kinds of trees: cherry, plum, apple, elderberry, box elder, maple, birch and willow, among others.  

(Photo by Marcie O'Connor)


Caterpillars hatch from these eggs and begin to eat. And eat, and eat, and eat, splitting their skin several times [according to Julie, they molt into different colors, too] . . . 

(Photo by Marcie O'Connor)



. . . until they are HUGE. Then, toward the end of the summer, they begin to construct cocoons. Cecropias are in a group called silk moths because they weave cocoons from their own silk, which comes out of a special spout on their lip.

At the top of the cocoon, the caterpillars leave an escape valve--a part of the mesh that's not so dense--so they'll be able to crawl out when the time comes.

The cocoons overwinter, attached to one of the host trees listed above.

(Photo by Marcie O'Connor)

IMG 1757

What happens inside these cocoons? How does a fat green caterpillar turn into something with feet and wings? After reading a fascinating article in Scientific American, I understand it this way:

1. As they grow, caterpillars develop "discs" inside their bodies full of special cells for each of the adult body parts it will need--discs for eyes, wings, legs, etc.

2. After they have spun their cocoons, the caterpillars' outer skin hardens into a case: this is when they enter the pupa stage.

3. As a pupa, the caterpillar releases an enzyme that basically dissolves all its tissues except the discs (no, I am not making this up). 

4. This protein-rich "tissue soup" fuels growth of the discs to form all the body parts it will need as a moth. This process is called . . . metamorphosis!

OK, now we're getting to the clinging and pumping part . . .

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