Caterpillars and population

For the past 3 weeks caterpillars have carpeted the outdoors, and when they can they sneak inside. Most of them are about 2 inches long, orange and black segmentally striped and covered with fuzzy tan fur. They move remarkably fast.

covered with caterpillars

It has changed the world we live in to have wiggly, crawly things where ever we step. It is  surreal–almost apocalyptic.  They are everywhere: all around the door, all over the walk, all over the road, chomping on my roses and my pear tree. They are western tent caterpillars and they like alders. Our house is surrounded by alder woods. A couple of years ago they were mostly on the north end of the island, and while Polly and Karl lay dying the caterpillars devastated their orchard. This year they have defoliated all the tall alders around our house, far back into the woods. My flowers are getting a lot more sun than usual.

This is how our trees look now, full of tents, leaves eaten away

I had renters in my guest apartment over the Memorial Day weekend — a single father and his two boys. I apologized for the caterpillars. Don’t worry, he said politely, the boys think they’re cute. Children seem to like them. My neighbor was out with his grandson biking past the yard as I was picking caterpillars off the vegetables I grow along the fence in half barrels. I said, Hi Sylvan, to the 4 year old. We have a pet caterpillar, he said. I laughed. We have an army of millions of them.

My vegetable garden

Every morning just after breakfast I go out with the broom and sweep up bags of them from around the door and the patio. We can’t use the patio anyhow, because a few minutes after I sweep there are caterpillars traveling purposefully in all directions. They drop on us as we sip our cocktails. So we stay inside. Jerry and I check each other for caterpillars when we have been outside. I spend hours every day picking them off the plants I grow. Now they are beginning to pupate, curling up the leaves and sticking them together with white cottony threads.

The house is covered with cocoons

I think about the ancient silk trade while I work picking them off in places I can get at them. I wonder why only silk worms make a fiber that is useful to humans. Why can’t we use the sticky white threads of the western tent caterpillar?

At first I couldn’t bring myself to touch the crawling caterpillars, but I got used to it and now I scoop them off the flower pots, walls and path by the handfuls, trying not to notice their soft, furry wriggling. I don’t want to squish them because yucky brown stuff gets on my hands if they are damaged. Rachel, the tall, beautiful young woman who pulls weeds for me sometimes (what a worker she is!) says, They make you resent them because you can’t help hurting them. But I have become angry with them. I want to kill them all.

The multitude of caterpillars is a striking example of the profligacy of life. There are live caterpillars crawling over squashed ones all over the road. My neighbors say they don’t walk on Granger Way these days because it’s so unpleasant to step on the crawling things. Millions are produced; so it doesn’t matter that only hundreds ever make it to reproduce. The biological strategy of the species is: blanket the world–some are sure to survive.

Apparently caterpillar numbers cycle and this is the worst they have been in 20 years. I have lived here that long and have never seen anything like this. Supposedly they don’t kill mature plants and trees, even though there are few leaves left on the trees in the woods. The eggs are laid in glistening packets around twigs of the trees. They hatch in the spring and the larvae (caterpillars) form tents packed with dense masses of them. At first they stay in the tents in the daytime and feed at night, coming back to their tents at dawn. They undergo 3 molts, each time getting bigger and after the last molt they leave the tent and set out on their life’s journey.

Birds are everywhere, but these caterpillars must really taste bad because no bird seems to feed on them. There is a kind of wasp that lays its eggs on them, and those unlucky caterpillars will never become the ugly brown moths which are the adult stage. If the wasps have laid their eggs on a caterpillar there is a distinct white spot on its head. When the moths emerge from their cocoons they have no mouth parts, and so they can’t feed. They mate, lay eggs for next years caterpillar infestation and then they die.

Every day now there are fewer crawling ones and more making cocoons all over the house and my plants. Jerry has bought a new pressure washer to clean them off the house, but it’s a monumental task. They are so sticky that he worries about getting water under the siding if he blasts them hard enough to loosen them.

Besides the multitude of caterpillars there is a sudden increase in the population of band tailed pigeons. They were not here, at least not such numbers, until this year. They coo mournfully and monotonously all day. The sound annoys a lot of islanders, some of whom want to shoot them. It has been suggested that they could become part of the trendy foraged food menu at the Willows. I just wish the pigeons would eat the caterpillars, but pigeons only seem to fancy black sunflower seed in island bird feeders.

Doves at the feeder

Is there a lesson to be learned from these population fluctuations? According to the journal Science the human population growth rate peaked in the early 1960’s, but it is still growing and will probably plateau at 9 billion in the middle of this century. The article goes on to discuss ways to feed this enormous number of people. The magazine The Economist, on the other hand, discussed “shrinking populations” and what governments are trying to do to get people to have more children. The Japanese in particular are not taking sufficient interest in procreation and the population is shrinking. Korea and China also have low fertility rates.

Are we going to have human population peaks and crashes like the caterpillars? What would the world be like if suddenly some lethal virus swept around the world and halved the population as the black death did in the 14th century?

Well, as Jerry and I say to each other when various disasters are predicted for the future, We won’t be around to see it.