Saturday, April 13, 2013

The Pipevine Saga

A Beautiful Pipevine Swallowtail Butterfly
Investing oneself in nature can be emotionally trying. We humans like cute baby animals and storybook endings. And when things don't turn out the way we expect or hope, it can feel like a sock in the stomach. But the natural world is unemotional. Living things exist within systems and interconnected webs, without good and evil and without judgement. The cute baby squirrel is nourishment for an equally deserving, but maybe not so adorable (to many people) snake. The green darner dragonfly struggling in a banana spider's web will give the spider strength to lay eggs at the end of the season. The mud dauber wasp paralyzes dozens of spiders, turning them into zombie food storage, to feed its larva. The heron spears the bullfrog with its long sharp bill and eats it as it struggles. The wind blows the cardinal nest full of eggs out of the tree, and they break on the sidewalk. I know intellectually that I shouldn't be sad, but then I can't help myself. I am a nurturer and a carer. I forget that it's a jungle out there, and start to cheer for one side or another. And that's where I get into trouble.

My current story started a 6 or 7 years ago when I had planted a Calico Flower/Dutchman's Pipe (Aristolochia elegans) in the yard. It grew huge, with strange, spotted pinkish flowers. One day I went out and saw several huge caterpillars munching the leaves. At that time, I was not raising the plants as caterpillar food, and I was a little upset to see my marvelous flowers being chewed back to the stems! But I got over it as I realized what I'd attracted to the yard.
Gold Rim Swallowtail Caterpillars
I thought at first that they were Pipevine Swallowtails caterpillars, because this was a Pipevine plant. But it turned out that they were the Gold Rim (Polydamas) Swallowtail caterpillars. I was able to watch one of them eventually form a chrysalis and then emerge as an adult butterfly. It was a fascinating experience and I looked forward to seeing this happen again the next year, because the plants were healthy and established. But then I learned that the Calico Flowers were class II invasive exotic plants and I was working on making my yard Florida Friendly. As I've written again and again, invasive exotic plants are not good to have in your yard. So I pulled out the plants and felt a little sad that I would not see the return of the butterflies in the spring. Determined to change this, the next year I purchased a native Wooly Pipevine (Aristolochia tomentosa), took it home, planted it and waited eagerly for the Pipevine Swallowtails, who supposedly use this plant as a host. Weeks turned into years and no swallowtails moved into our yard. I stopped believing that they would ever come. (In hindsight, I think that the butterflies knew that there had to be enough vines available for their larvae to eat and it took years to get to that critical mass of growth.) I would occasionally see Pipevine Swallowtails as they flew over and nectared on the flowers, but they didn't stop and move in. Finally, this spring, I saw what I thought could be a Pipevine Swallowtail butterfly wafting over the, now abundant, tendrils of pipevine! The butterfly flitted and touched each vine, then flew to another as she picked the perfect location for her eggs. The next day I went out and found a nice little zigzag line of tiny, geometric eggs. A day later I found another bunch, and in the following days I found several others, tucked all over the yard. Finally, our yard had made it!

A few days later, I went out to see the eggs and found that they had recently hatched! The caterpillars were so tiny, and I was so excited! I could see the minute creatures next to their empty eggs, which they were busily consuming for their first nourishment.

Day 1
I was fairly sure that they were Pipevine caterpillars, but I was not completely sure. I looked in my books and online and the eggs looked like they could have been Pipevine or Gold Rim. I couldn't see any photos of either type of caterpillars at that very early stage, so I decided to watch and photograph them as they developed. This turned into a project and I was invested. Danger! Warning! I never learn.

I observed them every day as they ate and grew. The eggs had been laid over several days, so their development was staggered. The first clutch would reach a milestone and the others followed the next days in order.

Day 2

Day 3

Day 4

Day 5

6 days in, they molted for the first time. As they outgrow their old skin cover, or "cuticle", they shed it and form a new one. They will go through 5 stages as caterpillars, called "Instars". After the 5th Instar, they molt into their chrysalis. After this first molt, they started to exhibit characteristics that made me fairly certain they were Pipevine caterpillars. For one thing, they had rather long fleshy appendages near their heads which I didn't see in photos of the Gold Rims. Also, I just wanted to have attracted Pipevines!

Day 6 (See shed molts off to the upper right)
Still small, the caterpillars stayed together and spent the days underneath leaves, hidden from predators and the sun. On day 7 I went to my usual spot for the first group, and something was wrong. Their vine lay on the ground, broken and withered. Tragedy had struck! But scanning the area, I was able to locate all of the group. Whew!

Oh no! Dead vine (with old cuticles stuck to underside)

Day 7

Day 8

Day 9
By day 10, the rest of the caterpillars had spread out and no longer clustered together. Their appetites were too big to share one leaf! I found one of the larger caterpillars next to its shed cuticle. Molt #2. Now I was certain that they were Pipevines. Look at those long tentacles!

Day 10, Molt #2
The caterpillars were growing quickly, but I could no longer find more than just 2 or 3 from each group. I just hoped that they had dispersed and had not been eaten. Supposedly, the pipevine is toxic and makes them taste bad to birds. I don't know if you can say the same for Anoles, though, and we've got a lot of them. On day 18, I looked all over and found only one large caterpillar, attaching itself with silk to a stalk of Society Garlic. I believe that it was getting ready for another molt. Looking closer, I could see that there was a dead caterpillar at the base of the same plant. I have no idea what happened to the dead one.

Day 11

Day 12

Day 13

Day 14

Day 15

Day 16

Day 17

Day 18
Then on day 19, the inevitable happened. I went out to check on the last caterpillar, and it was gone. Whether it had been eaten, or died of disease, or had just moved to a better vine, I'll probably never know. I also don't know if it was quite mature enough to pupate, although I'll keep looking around the yard to see if I can find a chrysalis. In any case, I felt pretty disappointed that all of those caterpillars were gone. It's a tough world out there, with lots of hungry predators and hazards. During those 18 days, we had freezing cold nights, some rain and scorching heat. Anything could have happened, and this is why the butterflies lay so many eggs. But as I look around the yard and see the scores of pipevine sprouts and the chew marks around the margins, I can feel fairly sure that the butterflies will continue to visit and the cycle will continue in the future. And if I'm lucky I'll be able to watch a Pipevine butterfly emerge from a chrysalis in my yard one day soon.

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