Month: May 2010

The caterpillar has changed a lot in the last week. Here it is 19 days after it emerged from the egg. It is about two inches long, and in my opinion, quite handsome.

Later that day it stopped eating and was still. Soon there was a yellowish stain and greenish stuff at the bottom of the cage. Caterpillars often empty their gut before making a chrysalis.

The next day the caterpillar wandered about the cage, apparently looking for a place to make its chrysalis. Finally it attached itself to the parsley plant (see above) and stayed this way for about 24 hours.

On day 21, I checked the caterpillar often, hoping to see it change into a chrysalis. From previous experience, I know that once the process begins, the caterpillar sheds its skin in a matter of minutes and reveals the chrysalis underneath. However, I missed the actual change and returned to find this chrysalis.

According to The Life Cycles of Butterflies, “During the chrysalis phase, the caterpillar liquefies inside the chrysalis and reorganizes, almost magically transforming into a butterfly. Even after decades of research, all the details of this metamorphosis are not completely understood.” I find all this quite amazing.

This book by Judy Burris and Wayne Richards is one of my favorite butterfly references and their website, ButtterflyNature.com, is another excellent source of information.

Now I wait, and hope to have a butterfly in a week or two.

The black swallowtail caterpillar has changed significantly since last week.  Instead of being dark with a white patch, it now has light green and black stripes with yellow spots.

Yesterday, I noticed the caterpillar was very still and wasn’t eating.  I wondered if it was okay.  Looking closer, I found it was beginning to molt (shed its old skin).

Caterpillars have a tough skin called an exoskeleton.  The skin doesn’t expand, so the caterpillar must shed its old skin to grow bigger.  The black blob in this image is the old skin.  The caterpillar also sheds its face mask, so its face is quite pale at first.  The feet are initially white, but turn black later.

A bit later, the caterpillar ate its old skin.  This is common and it is a way for the caterpillar to reuse the nutrients in the old skin.  This seems rather yucky to me, but it’s a good example of recycling!

Here’s the caterpillar in its new skin.  14 days after it hatched it is an inch long – 4 times longer than it was a week ago.  Talk about a growth spurt!

The black swallowtail butterfly caterpillar has emerged!

When I checked the egg last Tuesday at noon, I discovered it had turned dark.  I looked again at 4:30 and saw a small black dot.  Using a hand lens (a strong magnifying glass), I discovered the caterpillar was out and eating its egg shell.  By 6:30 the egg shell was gone.

Since then the caterpillar has been eating dill and growing.  As of  day six, it is about a quarter of an inch long.  It’s black with a small white patch in the middle and spines along its back.

I created a cage using a plastic shoe box (8 x 13 inches), nylon tulle from a fabric store, and elastic ribbon.  The dill is in a florist tube filled with water.  I’ll keep the cage indoors where there is plenty of light but no direct sun, and where I can watch it.

The caterpillar is the small black spot on the dill in the image above.  I look forward to watching it grow and change.