Saturday, September 3, 2011

Robin (Cecropia) Moth

Adult Male Cecropia Moth.
[photo: Irish Eyes/Morguefile]

I like how the dots at the end of the wing looks like they have electricity emitting from them like electrodes in a mad scientist's lab

Adult female Cecropia Moth

Stage five cecropia caterpillar

I have had the amazing experience of watching a final stage Cecropia caterpillar spin its cocoon, over winter in my garden and emerge as a huge, stunning moth in my dining room several months later. 

I was looking after children in my home and on a walk one of the kids found this brilliant, beautiful and monstrous caterpillar. As thick around as my thumb and over ten centimetres (4 inches) long. It had fallen from a tree and was lying like a treasure among composting foliage in a forest clearing. We brought it home and tended its welfare until it spun a terribly nondescript cocoon and proceeded bore the life out of the children, as nondescript cocoons are inclined to do. 

Following the instructions from someone in the Department of Entymology at the University of Guelph, I brought it into the house in March, placed it above the hanging light over my dining room table and forgot about it. It emerged quite silently and gloriously, one month later. I noticed it as I was walking by the table and something huge and amiss caught my attention out of the corner of my eye. It had not quite finished plumping out its wings yet I was immediately mesmerized. 

We all gathered around it, all of us - children and adults alike - equally stunned by its beauty and size. The moth itself is as subtle as the caterpillar is vibrant. Yet examining it closely I found a palette of lovely earth tones with peaches and lavenders highlighting the wings. However, I was saddened to realize its destiny was then to spend the next two weeks searching in vain for a mate. There were no other Cecropias alive the beginning of April. Here we were with a huge moth, unable to help it finish its quest. 

Since I could not stand to let it flap around my house, like a floppy bird, damaging its wings, I euthanized it and together with the pictures we took of the stages of its life I gave it to the father of the child who found it and he preserved it in acrylic for his kids. While I feel privileged to have had this experience, if I came into possession of another Cecropia cocoon now I would not manipulate its emergence until such time as it would have normally done so. 

Also known as the Robin Moth it is North America's largest moth. Rarely seen as it usually comes out at night the adult moth lives for less than two weeks after emerging. Having no mouth, it's only purpose is to find a mate and continue the species and it has seven to ten days to do so after which it dies of starvation. 

When I met my Cecropia caterpillar it was in stage five of five instars, or periods of molting. My Cecropia was male as indicated by his huge furry antennae once the adult emerged a few months later. As subtle and muted as the adult moth is, the caterpillar is a spectacular combination of pastels and iridescence. 

Here is a long, agonizingly tedious film (27 minutes!) of the whole life cycle. Skip ahead to about the twenty minute mark and watch how the wings unfurl from tiny wrinkled balloons to their full beauty. Cecropias must live in a climate where there is a winter period or their life cycle does not complete. They start the process of emerging as soon as a warm period occurs. It takes about a month.

Photos: 
This is an excellent series of the complete life cycle by Michael Cook who runs a Yahoo group for folks who raise silkmoths here.
These are a few pictures of the adult moth at my favourite bug site.
Photo of the adult Cecropia at the top I got from here

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