Tuesday, May 8, 2012

Raising Zebras

Frass Happens
We assumed the responsibilities for raising 50 orphaned Zebra Swallowtail caterpillars several weeks ago, a gift from Chris and Deb Barnhart.  They needed a place to feed on pawpaw and we had a large grove on our ridge top woodland.  We are sworn to secrecy on their paternity, but were assured that they were legitimate.

Each dozen (or more- who knows with these tiny caterpillars) were in a container with leaves nestled on a coffee filter.  The filter was to be attached to the trunk of a small pawpaw and then the tree covered with a white mesh bag.  It is designed to let in air and sunlight but exclude birds and small predatory wasps that might want to lay their eggs on our cats.  Once the bag is secured, the cats crawl all over the little tree, devouring the leaves and producing an awesome pile of frass in the bottom of the bag.  Yes, frass is just what you think it is, known among school children by the other scientific term, poop.

Note Silk Trapeze
Friday was the scheduled birth date.  Like most dates of spontaneous delivery, (there are no C-sections or inductions for our organic caterpillars) there is a lot of variability.  We took off the first two bags and found that while most of the cats had formed their chrysalis, several in each bag were still crawling around, looking for a good place to "hang out."

We waited 3 more days before opening the last bags.  Most of the cats had formed their chrysalides and we put the other few cats in a container with some sticks and leaves for them to attach to.  All but two of these pupated over the next 24 hours.

When butterflies form a pupa (called a chrysalis), they weave a silk trapeze around the top to hold their future body upright.  (See picture)  Inside, the caterpillar turns to a mass of goo, then miraculously reconfigures into a butterfly.  The silk keeps the butterfly head up so that when it emerges, gravity will help pull its wings as they inflate and dry fully extended.  Chris and Deb will hang the chrysalides in the house in this same position.

Friendly Zebras
Newly Emerged

Chris Barnhart's Zebra color wheel
For a beautiful set of Zebra Swallowtail pictures at all stages, go to Chris Barnhart's page.
His unusual facts page is on the FOG News Blog.
Details of the Zebra/Pawpaw connection are at Blueridgediscoveryproject.blogspot.com

1 comment:

  1. How did they hang the chrysalis? My first parsley crop this year has led me to raising Black Swallowtail Caterpillars - 33 to date...although 21 are still in the the caterpillar stage. The BST's led to Monarchs found on milkweed on a friend's farm. I just LOVE watching these guys! My email is kellyknits@comcast.net