The View From Mudsock Heights: Where did the little tomato worms go? Is their cycle a secret?
By Dennis Powell
July 14, 2008
Many years ago, I worked with the financial columnist Sylvia Porter, who was an expert on business and economic cycles. She had determined that much in economics is cyclical, following a repeating pattern. If one viewed the whole pattern, she believed, one could have a sense of what might happen next.
This was complicated, she realized, by the fact that not everything economic is on the same schedule, and that different economic factors played off each other, and rarely did their cycles coincide.
It made prediction difficult. Trying to base a decision on only part of a cycle, or failing to take into account other factors and where they were on their separate cycles, could spell financial ruin.
I had cause to think of this the other day, when we were sitting on the porch swing and I noticed something strange at the top of a tomato plant. I thought that a bindweed had found its way to the plant and was now reaching its spindly, wiry self skyward. On inspection, though, I discovered it was a denuded stem from the tomato plant itself. Now it was a matter of careful searching. Sure enough, there, several stems down, was a fat and happy tomato worm, and I am pleased to say that it will not be turning into a sphinx moth.
This got me to wondering. Some years, every tomato worm seems covered with the pupae of tiny parasitic wasps, whose larvae suck the life out of the worm, causing its fascinating life cycle to come to an end there and then.
Some years, the wasps are nowhere to be found and the tomato worms are, like this one, in fine health until someone squashes them.
Some years there is no evidence of either worm or wasp.
What can we make of this? Is there an identifiable cycle of the relationship between the tomato worm and the braconid wasp that parasitizes it?
It is a complicated problem and, lest there be disappointment, let me hasten to say that I do not know the answer. I suspect that there is in fact a cycle that could be graphed, and that perhaps it goes something like this: One year, many tomato worms. Next year, many tomato worms, but they’re covered with wasp pupae. Next year, there are few tomato worms, so there are few hosts for the little wasps. Next year, there are plenty of healthy worms and few wasps.
Absent other factors, it might work out that way. But there are other factors. There are always other factors.
Last year was very dry. This year has so far been very wet. The winter of 2006-2007 got colder than the winter of 2007-2008 got, though this year is seemed to stay colder longer. Would this have affected the life cycle of either of the organisms?
Perhaps the relationship between the two was altered by the mixture of plants I have in the garden this year, or when and how I tilled the soil. I cannot know.
Nature, like economics, is very complicated, with many factors involved, all subtly interacting. There is no way to take into account all the variables. Sometimes all we can do is react.
The relationship between the tomato worm and the little wasp is one tiny example. There are others. For example, last year there were fewer Asian ladybugs than in previous years. The drought was blamed. It will be interesting, possibly in a very irritating way, to see if they bounce back this year. Perhaps they are like a meteorological Goldilocks, doing poorly when it is too dry, and poorly when it is too wet, and thriving only when it is just right. Or it could be that something entirely unrelated to the weather is the governing factor.
It is part personal proclivity and part experience that makes me skeptical of most explanations, most cause-and-effect analyses, and the more certain someone is of the explanation, the more skeptical I become. It could be, for instance, that human beings are causing cataclysmic global warming. Or it could be that such warming is taking place due to factors that have nothing at all to do with us. Maybe it’s not happening at all. It could be that there is an entirely natural cycle in play and that we do not understand it. It could be that those who argue for (and those who argue against) it have agendas that have little to do with climate. A generation ago, the magazines and scientists were sounding the alarm about the new ice age that was coming. (The suggested remedies, interestingly, were the same as the ones proposed to stave off global warming. Odd, isn’t it?)
I don’t think there’s a way of knowing. Nature is very, very complicated — there are many factors, and few of them sit still. They all have their own cycles. Trying to figure out how they all fit together will probably be a mystery pretty much forever. We cannot predict the weather — or the stock market — a month in advance.
But we can certainly watch, and wonder, and, when we see a tomato worm, squash it.
Editor’s note: Dennis E. Powell was an award-winning reporter in New York and elsewhere before moving to Ohio and becoming a full-time crackpot. His column appears on Mondays. You can reach him at dep@drippingwithirony.com.
Comments
Please log in to post a comment.
