Animal Life - Caterpillarsby Janet Partlow Here in early September, the sun is still beating down strongly in the last dying days of summer. This is a time when many animals are dashing/flying/crawling around taking advantage of summer, getting ready for harder weather to come. For example, one day as I am sitting out on the patio, basking in the sunshine and enjoying the flowers in my butterfly garden, my eyes are caught by tiny movements on the late-blossoming fennel. When I go to investigate, I find a pair of Anise Swallowtail caterpillars marching up and down the stems of the flowers, chowing down on the pollen-rich flower spikes. At some point a few weeks ago, an Anise Swallowtail butterfly must have been visiting my garden. Besides using the nectar in the flowers, she also was looking for healthy host plants on which to lay her eggs. She only uses plants in the carrot family and is particularly attracted to carrots, dill and fennel. She laid minute single green eggs somewhere on the stem. About two weeks later tiny caterpillars chewed their way out of each egg sac and started eating the fennel. Thus was my garden gifted by caterpillars. Each day we go out and check their progress. They are truly beautiful: fat and succulent, with vivid green, black and yellow stripes. When they sense our presence, they freeze up on the stem and play dead. But if sufficiently provoked, they arch up and push out soft bright orange horns from their heads, making them look fearsome indeed. As we watch them over the next ten days, they eat and eat and eat, growing visibly each day. However, they reach a point of growth where the skin will no longer stretch; at those times, they stop eating, find a place to remain quiet for awhile, and molt, pushing off the old skin like pulling off a dirty sock. Then they start eating again, with renewed & voracious appetites. Our swallowtail caterpillars go through three molts, or instars. After the third instar, they get huge - maybe one and a half inches long. They are frantically eating and the results are visible on the fennel. After several days of this behavior, they get restless, going on walkabout. At this time they are looking for a safe place to go through the final molt into a chrysalis. When our caterpillars went on walkabout, we lost track of them. But we know that somewhere in the butterfly garden, they looked for a sturdy stick. They crawled up, cast a silken line around themselves to anchor firmly in place, hung by their bottommost feet and cast off their last skin. In 24 hours, a brown sack-like chrysalis will be firmly attached to the stick; to our eyes it will seem dead. But inside the chrysalis, the genetic code of the swallowtail is keeping it dormant in a winter holding pattern. In the next several months of rain, ice and snow, the chrysalis will keep the butterfly safe. Sometime next March, after a week of sun and warmer temperatures, genetic codes and magic and life itself will stir. The butterfly will form, will break open the stiff brown walls of the chrysalis and will crawl out to face another spring. And the next year's Anise Swallowtail butterflies will take flight. Janet Partlow is a staff writer for the Green Pages.
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